Syria's civil war has reinforced Iraqi state weakness and fears of partition along ethno-sectarian lines. The conflict has encouraged the proliferation of militias, refugee flows and Kurdish transnationalism, all of which challenge Baghdad's sovereignty and enhance the de facto authority of sub-state actors. These centrifugal forces have been compounded by Iraq's political and financial crises, the onslaught of the Islamic State of Iraq and al-Sham (ISIS), and second- and third-order consequences of the anti-ISIS campaign. Militias, ISIS militants, the Kurdistan Worker's Party (PKK) and other radicalized groups move regularly across the porous Iraqi and Syrian borders, aggravating ethnosectarian fissures. Underlying these challenges to state cohesion are assumptions that Iraqi nationalism is no longer salient, that current borders are "artificial" and therefore unsustainable, and that ethnically and religiously homogenous political units are more authentic and viable means of governing and stabilizing states.¹

Yet, despite Syria's spillover and its sovereignty-undermining effects, the Iraqi state has not collapsed or been rendered obsolete.² Regional actors and most local populations remain committed to Iraq's territorial integrity even if they benefit from state weakness. Iraqi nationalism also persists among Arab groups — Sunni and Shia alike — alongside intra-communal divisions and alliances that cross ethnosectarian lines. Kurdish communities are fragmented as well, despite their distinct nationalist sentiment. Consequently, instead of a "Syriaq" under a Sunni Arab caliphate, a cohesive "Shia crescent," or an independent Kurdistan, the Iraqi state has remained intact, while breaking down into an amalgam of hyper-fragmented entities seeking some form of self-protection and self-rule. What are the implications of these dynamics for Iraqi cohesion and regional stability?

SHIFTING SOVEREIGNTY

Challenges to Iraq's authority and territorial cohesion commenced decades before the Syrian civil war, despite the country's juridical sovereignty.³ Even after the Treaty of Sevres (1923) delineated the boundaries of former Ottoman territories and the Iraqi state gained official independence from Britain in 1932, the country was neither fully sovereign nor unified. Sunni Arab, Shia Arab and Kurdish communities were divided by sect and ethnicity, as well as by territories, tribes and politics. Some continued to support their Sunni Muslim cohorts in Turkey against British rule, while others accommodated the new mandatory power.⁴ Certain Kurdish groups opposed the new territorial divisions that denied them a state of their own, while most others did not. These contestations and internal divisions continued after Iraq's violent revolution of 1958 that overthrew the British-backed Hashemite monarchy and played out through competing notions of Iraqi nationalism, unstable governments and Kurdish uprisings.

The consolidation of Baathist rule in 1968 checked (but did not remove) sub-state challenges and strengthened Iraqi sovereignty; the state had gained a monopoly of force within its territorial borders. Then-Iraqi-vice-president Saddam Hussein may have negotiated the 1970 Autonomy Agreement with Kurdish leader Mullah Mustafa Barzani, but he ensured that Baghdad and not the Kurds would control the northern autonomous region. State sovereignty and territorial cohesion were reinforced by a unified Iraqi army, a centralized intelligence apparatus, a state-led economy, and state-building policies that Arabized citizenship, territories and oil resources. Most important was the oil-rich province of Kirkuk, as well other northern territories populated by Kurds, Turcomans, Arabs and other minorities in northern Iraq.⁵

Still, Iraqi sovereignty and authority, which was largely rooted in violence and oil rents, remained vulnerable to external influences. The Islamic Revolution in Iran (1979), the Iran-Iraq War (1980-89), and the rupture of official ties between Damascus and Baghdad from 1979 to the 1990s and the Gulf War (1990) altered the regional balance of power and left Iraq economically and politically weakened.⁶ Neighboring countries also engaged in "sovereignty-undermining behavior" even if they supported Iraq's territorial integrity.⁷ Iran, Turkey and Syria regularly backed Iraqi Kurdish political parties — Masoud Barzani's Kurdistan Democratic Party (KDP) and Jelal Talabani's Patriotic Union of Kurdistan (PUK) — as local proxies to undermine Baghdad, rival Kurdish groups and each other.

Iraqi sovereignty was further weakened by shifting international norms and external interventions. UN-imposed sanctions and the creation of no-fly zones in southern and northern Iraq and a safe haven for the Kurds after the Gulf War increased the gap between Iraq's juridical and de facto authority. These trends persisted after the U.S.-led overthrow of Saddam in 2003. Rapid de-Baathification, the dismantling of the Iraqi army, and the 2005 constitution codified state weakness and created incentive structures based on three dominant groups: Sunni Arab, Shia Arab and Kurd. Ethnosectarianism was exacerbated by former Prime Minister Nuri al-Maliki's policies, the retrenchment of Sunni Arabs from the political process (2005-10), and the al-Qaeda insurgency.⁸

On the eve of the Syrian civil war, Iraqi sovereignty had been significantly weakened. Sub-state actors had gained de facto control over ungoverned spaces and their resources, posing a significant challenge to state authority. The Kurds in particular had benefitted from a weak Iraqi state and external patronage by shifting the notional "Green Line" — a UN boundary created in 1991 to separate Baghdad-controlled territory from the Kurdish Autonomous Region — and assuming de facto control over parts of disputed territories in northern Iraq. Some Sunni Arab communities, as well as Iranian-backed Shia militias, continued to contest state authority and fuel sectarianism. These dynamics were reinforced by regional states, namely Iran, Turkey and Saudi Arabia, which were seeking to exert dominance in the Middle East and create spheres of Sunni and Shia influence.

PROLIFERATION OF MILITIAS

The Syrian civil war may not have caused Iraqi state weakness or sectarianism, but its spillover effects have created additional challenges to Iraqi sovereignty.⁹ What began as a popular uprising against Syrian president Bashar Al-Assad has developed into multifaceted, hyper-localized conflicts between and within communities. One driver of these conflicts is sectarianism, which has been largely instigated by regional actors. Networks in Turkey and the Gulf States (Saudi Arabia, Qatar) have supported the armed Sunni Arab resistance tacitly or directly by channeling funds and weapons through Syrian members.¹⁰ Assad in turn, has relied on Iran's Islamic Revolutionary Guard Corps (IRGC), IRGC-backed militias from Iraq and Lebanon (Hezbollah), and Shabiha forces to counter the proliferation of militant Sunni Islamic groups including ISIS, protect Shia holy shrines, and revive the weakened Syrian army during the war.¹¹ IRGC-backed groups also gained prominence as part of the "axis of resistance" against ISIS in Iraq and Syria. Their rise coincides with the emergence of Iraq's popular mobilization forces (PMFs), which were empowered after the fatwa of Iraqi Grand Ayatollah Ali Al-Sistani in 2014.¹² Although Sistani's fatwa was not sectarian and called on all Iraqi citizens to combat ISIS, only the Shia initially responded. Some militias have been further empowered by their battlefield victories against ISIS and opportunities to fight in Syria. Assad's offensive to retake southern territories, for instance, included the Syrian Army, Hezbollah, the IRGC and the Iraqi militia Kataib Sayyid al-Shuhada.¹³

Indeed, extremist individuals and militias — both Sunni and Shia Arab — were active in Iraq before the Syrian civil war.¹⁴ In the Iraqi province of al-Anbar in the early 2000s, for instance, the Syrian Sheikh al-Nabhan created sharia institutions, while Sheikh Kamal Shakit became the sheikh of Falluja's Great Mosque. Sheikh Abdulla al-Janabi led anti-American uprisings and later took refuge in Aleppo.¹⁵ Different Iraqi governments have also used local militias as surrogates for the military, police or intelligence services to consolidate power and control territories.¹⁶ Saddam attempted to "coup-proof" his own military by relying on the Fedayeen as an irregular tribal militia to assure that no single group would be predominant. Immediately after 2003, Islamic groups that were closely controlled by Saddam or functioned underground, including the Iraqi Islamic Party (IIP), were reactivated and became influential in the Sunni Arab Baghdad-Ramadi-Mosul triangle.¹⁷ Iraqi Sunni Arab nationalists joined or tacitly supported militant Islamic and radical Arab-nationalist groups that emerged, aiming to develop and support AQI until it achieved the level of a caliphate.¹⁸ Former Baathist officers also acted according to Saddam's January 2003 directive and turned to the Shia hawza (religious establishment), expatriate ayatollahs and Baathists in exile in Syria as part of their early resistance strategy.¹⁹

Still, after 2011, as the Syrian state weakened alongside Iraqi state breakdown, militias had even greater opportunities to proliferate, radicalize and stir sectarian tensions. The uprising against the Assad regime inspired those Iraqi Sunni Arabs who regarded it as part of a broader struggle against Iranian influence and a discriminatory Iraqi government. Some Iraqi tribal leaders from Anbar traveled to Syria to support Sunni Arab fighters. Other Sunni Arabs and former Baathist officers joined local insurgents, including the Jaysh Rijal al-Tariq al-Naqshabandi (JRTN), to create al-Qaeda affiliates to replicate Syrian Sunni Arab groups or recruit local fighters for the Syrian war.²⁰

Weakened state sovereignty and porous borders in Syria and Iraq have enabled militias and radicalized groups in another way. By 2007, local Sunni Arab Iraqi militias were not only engaged in the AQI insurgency; they controlled entire sectors of the economy, including taxation and import-supply chains, and the former oil-for-food smuggling network that extended from Jordan through Iraq's Sunni Arab cities of Fallujah and Mosul, the Kurdistan Region, Turkey and Syria.²¹ These smuggling networks expanded after the outbreak of the Syrian civil war in 2011, when militant groups such as the al-Nusra Front and Sunni Arab tribes took control of key Syrian oil fields in Deir al-Zor, as well as affiliated road networks and supply chains. By December 2013, six months before the Mosul takeover, ISIS had controlled smuggling networks into Syria, Jordan and Turkey and was generating about $8 million monthly.²²

Similarly, the empowerment of IRGC-backed PMFs has undermined the Iraq government's efforts to stabilize former ISIS safe havens and reintegrate Sunni Arab populations into the state. Despite the vetting process conducted by Iraqi security officials in liberated ISIS territories, in some localities IRGC-backed PMFs (Badr Brigades, Asaib Ahl al-Haq and Kataib Hezbollah battalions) have taken over checkpoints and refuse to allow some Sunni Arab internally displaced persons (IDPs) to return to their homes.²³ These obstructions are prevalent in areas with mixed Sunni and Shia Arab populations, where oil resources and assets are present and territories are disputed.

The presence of IRGC-backed PMFs also continues to fuel intracommunal divisions. While many Sunni Arab IDPs have indicated their willingness to cooperate with Iraqi Security Forces (ISF), Kurdish Peshmerga and some Sistani affiliated PMFs, none are willing to accept the presence of IRGC-backed PMFs in their territories. The vast majority of Iraqi Shia communities, however (and some Sunni Arabs and Kurds), consider the PMFs the most effective fighting force and "the only reason that Baghdad continues to exist as the capital of Iraq."²⁴ Still, the PMF status in Iraq remains contentious. Although in November 2016 the Iraqi parliament passed legislation that established the PMF as an entity within the Iraqi armed forces, about one-third of the parliament opposed it and boycotted the session.²⁵

REFUGEES AND TRANSBORDER KURDISH NATIONALISM

Iraq's internal sovereignty has been further challenged by the economic and political fallout of the Syrian refugee influx and transborder Kurdish nationalism. By June 2016, about 240,000 registered Syrians (81,250 households) had taken refuge in Iraq, the vast majority of whom are Syrian Kurds in the Kurdistan Region. Smaller refugee communities are hosted in other parts of northern Iraq's disputed areas and Anbar province, about 85,000 in Erbil alone.²⁶ While the UN High Commissioner for Refugees (UNHCR) and the International Office of Migration (IOM) are providing much-needed humanitarian support and limited financial assistance, the refugees have added to the financial pressures of the Iraqi government and the KRG. Both are virtually bankrupt due to the dramatic decline in oil prices since 2015, increased security costs of the anti-ISIS campaign and financial mismanagement. The Syrian refugee spillover coincides with other significant demographic movements tied to the ISIS threat: the presence of nearly three million IDPs — mainly Sunni Arabs across Iraq — and about 10 million Iraqis in need of humanitarian assistance.²⁷

These pressures are likely to persist in the near to medium term, particularly if Syrian refugees become a permanent population. For instance, in the Arbat camp in Suleymaniya, which hosts about 6,700 Syrian Kurds (1,751 families), the refugees have replaced their tents with concrete homes.²⁸ While many refugees have sought jobs outside the camps (Syrians, particularly women, are willing to work in service-sector jobs that Iraqi Kurds will not or cannot do), they depend on community services, schools, health care, employment and education that demand support from the Iraqi government and the KRG, as well as the United Nations. Competition for jobs during a period of economic downturn has also led to tensions among refugee communities and local populations, adding more pressure on the government to fill the administrative and security gaps.

Syrian refugee flows also have had political implications. They have enhanced the authority and patronage networks of the KRG, particularly Masoud Barzani, since international aid is largely transmitted through KDP-controlled camps and nongovernmental organizations. Additionally, the vast majority (94 percent) of Syrian refugees are Kurds from the Syrian border town of Qamishli, where Iraqi Kurdish parties, particularly Barzani's KDP, have historically exerted influence.²⁹ Given their proximity to the Iraqi Kurdish border, Syrian Kurdish refugees have largely settled in Dohuk and Erbil governorates, also controlled by Barzani's KDP, with spillover into Suleymaniya, controlled by the PUK and Gorran groups. The Iraqi government in Baghdad has little influence over these communities, who look to the KRG and Kurdish political parties to assure their well-being.

Kurdish authority and challenges to Iraqi sovereignty and cohesion have been reinforced by Syrian Kurdish nationalism. Although transborder Kurdish politics did not begin with the Syrian war, it had new opportunities to flourish with the breakdown of the Syrian state, alongside a weakened Iraq.³⁰ Since the withdrawal of most Syrian army forces from northeastern Syria in 2012, the Syrian Kurdish People's Protection Forces (YPG), the armed wing of the Democratic Union Party (PYD) and an affiliate of the PKK, have taken de facto control of oil resources in Hasakah province (Rmeilan Field) and the strategic Iraq-Syrian border crossing points in Rabia. Syrian Kurds have also benefitted from the anti-ISIS campaign. The U.S.-led effort that works "by, with and through" local partners has relied heavily on the PYD as a leading actor among the Syrian Democratic Forces (SDF) and the most effective anti-ISIS force in Syria.

U.S. and coalition support has inadvertently empowered and semi-legitimized the PYD, enabling it to create new facts on the ground that strengthen its influence in Syria and across borders. Since the anti-ISIS campaign started, the PYD has expanded its territorial control by about 186 percent, established three autonomous cantons called Rojava, and declared a "federal Kurdish region."³¹ It has also used battlefield victories to mobilize transborder Kurdish nationalist groups. The expulsion of ISIS from the Syrian Kurdish town of Kobani, for instance, created new nationalist myths and symbolism that have affected Kurdish communities in Iraq, Turkey and Iran. The PKK gained credibility among Kurds by defending Yezidis in the disputed Iraqi territory of Sinjar after the ISIS onslaught in August 2014 and the withdrawal of some KDP Peshmerga from the area. PKK forces are also present in Kirkuk and other localities to counter ISIS, alongside some Iraqi Kurdish Peshmerga forces (PUK). Consequently, a large part of the Iraqi Kurdish masses regard the PYD as "true nationalists" who continue to struggle for the Kurdish cause amid the corruption and bankruptcy of their own government.

Iraqi Kurds, in turn, have used the Syrian war and PYD successes to help authenticate their nationalist credentials and agenda. During the battle for Kobani, the Iraqi Kurdistan parliament voted to permit its Peshmerga forces, apart from the ISF, to deploy to Syria in support of their ethnic brethren. Iraqi Kurdish officials also continue to meet with different Syrian Kurdish leaders and sponsor conferences and events on their behalf inside the Kurdistan Region. The PYD has representatives in the Iraqi Kurdish city of Suleymaniya, where it can further maintain contact with PKK headquarters in the Qandil Mountains. Other Syrian Kurdish representatives tied to the Kurdish National Council (KNC), an opposition group backed by Masoud Barzani comprising Iraqi Kurdish party affiliates, are based in Erbil. These crossborder dynamics have further emboldened the idea of "Kurdistan" as a distinct territorial unit within or apart from the state, or as a transborder entity.

STATE RESILIENCE

Given these centrifugal forces, why has the Iraqi state not collapsed or split along ethnosectarian lines? In many areas, non-state actors and their militias have greater authority than the central government. Sunni Arabs continue to feel alienated from the state, and Kurdish groups are seeking greater autonomy, if not independence. Yet, instead of breaking up into three cohesive and homogenous regions, the Iraqi state has become hyper-fragmented; sub-national groups have divided internally based on territorial units tied to distinct local, tribal, economic and political-party interests. Each group seeks some form of self-rule and self-protection and is strategically using borders, territories and resources to control revenue and build patronage networks.³² What explains the resilience of Iraqi borders and hyper-fragmentation of the state, and what are the implications for Iraqi and regional stability?

Iraq state resilience reflects the ongoing regional commitment to the territorial integrity of states, the persistence of Iraqi nationalism, and intra-communal divisions. Despite geopolitical tensions and competitions, key regional actors such as Turkey and Iran have a shared interest in keeping Iraq's external borders intact. In fact, the breakdown of the Syrian state, the empowerment and expansion of the PKK, rising Syrian Kurdish nationalism, the failed Turkish coup of July 2016, and increased ISIS terrorist attacks inside Turkey have heightened Ankara's threat perceptions. Instead of backing an Iraqi Kurdish state, Turkey has reacted by affirming its commitment to Iraq's territorial integrity and state-to-state relations with the Iraqi government. Ankara also continues to strategically leverage its interests in a unified Iraqi state. It has carved out a sphere of influence in northern Iraq to include a Kurdish buffer zone and Sunni Arab support base in Nineveh province. This sphere is based on a shared Sunni Muslim affiliation, commercial opportunities, access to hydrocarbons, close personal ties between Turkish President Recep Tayyip Erdoğan and Masoud Barzani, and security priorities — particularly checking the PKK and countering Iranian influence. Similarly, Iran benefits from a weakened Iraqi state and has created its own zone of influence among Shia and Kurdish groups. Yet it continues to affirm Iraq's territorial integrity and opposes any attempt at Kurdish statehood.

The Iraqi state also remains resilient due to the salience of Iraqi nationalism. Despite the proliferation of militias and radicalized groups that stir ethnosectarian sentiments, the vast majority of Iraqi Arab populations — both Sunni and Shia alike — are Iraqi nationalists. Many Sunni Arabs may continue to criticize the Iraqi government, oppose Iran, and seek some form of local Sunni Arab autonomy, but they remain committed to Iraq's territorial integrity. In fact, threats to state sovereignty, particularly by external actors, have been a unifying issue for most Iraqi populations regardless of ethnic and religious affiliation. For instance, in response to Turkey's threat to militarily intervene in northern Iraq as part of the anti-ISIS effort, most Iraqis, with the notable exception of former Nineveh governor Atheel al-Nujaifi and Masoud Barzani, strongly opposed it and coalesced around Iraqi nationalism. Most Iraqi Arabs and some Kurds also support Baghdad's authority over oil exports and revenues, in conjunction with provincial administrations and the KRG, for the benefit of all Iraqi populations.

Even if Iraqis were not fully committed to state sovereignty, ethnosectarian partition would not be viable due to the deep divisions within communities. A "Sunnistan" cannot come into being; Sunni Arabs lack a cohesive territorial unit, a single charismatic leader, or a shared political agenda. Some Sunni Arab groups in Mosul are aligned with Atheel al-Nujaifi and backed by Turkey, and seek to create a distinct Sunni Arab region within Nineveh province. Others in Nineveh reject this plan. Similarly, some Sunni Arabs in Anbar are cooperating with Baghdad and want a strong central government along with local self-rule; others oppose the Iraqi government and fellow Sunni Arab tribal leaders. Still other Sunni Arab leaders seek greater decentralization within existing provincial boundaries. The ISIS threat has reinforced these divisions. Intra-Sunni power struggles are playing out as former ISIS territories are liberated and revenge attacks take place against individuals and families tied to ISIS (or perceived to be). Different Sunni Arab personalities backed by regional states are also competing to gain influence in Baghdad and outlying areas.

Similarly, Iraqi Shia Arabs are not a unified community. Despite calls by some Shia provinces for greater autonomy, Iraqi Shia Arabs do not seek to separate from Iraq or create a "Shiistan". Rival Shia groups, including those affiliated with the Iraqi reform movement that challenges the authority of Prime Minister Haidar al-Abadi, have obstructed a unified Shia political force or Shia territorial entity. Basra and other oil-producing provinces in southern Iraq may seek greater autonomy and control over their oil revenues, but their claims are based on existing provincial boundaries and predicated on Iraq's territorial integrity.

Nor have Iraqi Shia made any serious effort to create a Shia crescent that includes Alawites from Syria and Iranians, even if they support them against ISIS and radical jihadists. The vast majority of Iraqi Shia are Iraqi nationalists and have resisted Iranian efforts to violate Iraq's territorial integrity. For instance, after the 2013 elections, Grand Ayatollah Sistani blocked Iran's attempt to keep former Iraqi Prime Minister Nuri al-Maliki in power, despite Tehran's aggressive lobbying. Iraqi Shia and various PMFs are also divided among competing power centers tied to local religious and political leaders influenced by Iran or Al-Sistani. Further, the Iraqi Shia religious establishment (marja-iyya) plays an important role in bridging sectarian divisions between Sunnis and Shias at a societal level. In fact, sectarianism has dissipated in some areas, as a consequence of ISIS, battlefield victories of the ISF and PMF, and efforts of Prime Minister Haidar al-Abadi to alleviate sectarian divisions.

Even the Kurds have failed to fully or consistently reject the Iraqi state, despite their ongoing threats to secede.³³ The KRG remains landlocked and dependent on Baghdad (and Turkey) for revenues and support, and benefits from it. The Kurds may continue to export oil and run their own affairs, but they have not assumed full or legitimate control over disputed territories or non-Kurdish populations, many of whom want to remain tied to Baghdad rather than the KRG. Further, Kurds are fragmented within and across borders. Although the PYD has de facto control of parts of northeastern Syria, it is not supported by all Syrian Kurds, including the KNC and conservative groups that oppose its atheism, leftist ideology and attempts to engineer social change.³⁴ The competition between the PYD and the KNC, mainly Barzani-KDP elements, has been violent at times and includes arrests, kidnappings, killings and border closures.

As the PKK has expanded its area of operations, Kurdish power struggles have spilled over into northern Iraq. The two leading Kurdish nationalist trends, the PKK and KDP, are competing for influence over territories, populations, revenues and leadership, and rely on different sources of patronage: Baghdad/Iran and Turkey, respectively. This competition is also occurring as other Iraqi Kurdish parties seek to check Barzani's power in the Kurdistan Region. For instance, while most Iraqi Kurdish parties support the PYD and recognize the Syrian Kurdish cantons and declaration of autonomy, the KDP, which is closely tied to Ankara, remains opposed. Instead, the KDP/KRG is training its own Peshmerga forces to send into Syria, a mission the PYD has rejected.

Thus, instead of merging their geographically contiguous territories under a quasi-unified entity, KDP officials have built trenches between Iraqi Kurdish borders and PYD-controlled regions in Syria (although the KDP and PYD also engage in cross-border commerce and smuggling).³⁵ The trenches are also aimed at keeping out ISIS terrorists and preventing KDP rivals — Gorran and the PUK — from supporting and supplying the PYD. Divisions among the KDP, PUK and Gorran Movement are also manifested in the absence of a unified Peshmerga command, a Kurdish parliament that has not convened since October 2015, and two virtual de facto administrations in Erbil and Suleymaniya.³⁶ These political fissures have been exacerbated by the KRG's financial crisis and Turkey's and Iran's penetration into Kurdish affairs.

The complexity of the hyper-fragmented Iraqi state can be seen in northern Iraq's disputed territories, which comprise Sunni Arabs, Kurds, Turcomans (Sunni and Shia), Yezidis, Assyrian, and other minorities that seek some form of local autonomy. Within each community some members support the Iraqi government, others want to be tied officially to the KRG, and still others oppose both — with no real agreement on how to administer their territories. The Yezidis are also split between PKK supporters and those backing Barzani's KDP. The former is tied to the Sinjar Yazidi Council and has recently formed a defense force to "formalize Sinjar autonomy" (there are seven different armed forces in Sinjar).³⁷ In other localities such as Diyala, which borders Iran, cleavages exist between the PMFs, Kurdish Peshmerga and Sunni Arab groups. Similar divisions exist in the mixed town of Tuz Khormatu in Salah al-Din province and compete among and within provincial administrations, the KRG and Baghdad.

CONCLUSIONS AND IMPLICATIONS

This detailed analysis has implications for Iraqi and regional stability. The spillover of the Syrian war — the proliferation and movement of militias, refugee flows and transborder Kurdish nationalism — did not cause Iraqi state breakdown, but it has further undermined Iraq's internal sovereignty. The Iraqi government no longer has a monopoly on force within its territorial borders and must compete or coordinate with sub-state actors. Many of these continue to be sourced or supported from Syria. State weakness has also encouraged regional states to cross Iraqi borders to advance sectarian agendas and stir proxy conflicts. As long as these conditions persist and official mechanisms to control borders are not reinforced, the Syrian spillover effects will continue to destabilize and weaken the Iraqi state.

Equally important is what has not happened to Iraq. Despite popular narratives of the "end of Iraq," "inevitable Kurdish statehood" or a "Sunnistan," the Iraqi state has remained strikingly resilient. This challenges the primordialist assumptions tied to ethnic and religious-identity politics. It shows that there is no direct correlation between weak states and the emergence of ethnosectarian entities. Sunni Arabs, Shia Arabs and Kurds may emphasize particular group attributes under given conditions. However, they are also bound by historical legacies, political spaces, economic interests, geopolitical realities, patronage networks and borders that have become institutionalized over time. Ethnosectarian groupings are neither more authentic nor a more stable form of political order than other formations. They have become salient because incentive structures in the post-Saddam federal Iraqi state enabled, if not encouraged, them to do so.

The real security challenge then, is not Iraqi state break-up or partition into ethnosectarian regions. Rather it is the continuation of state weakness and the proliferation of hyper-fragmented entities that both depend on the state and challenge its authority. Small landlocked entities are not self-sustaining, no matter how much they oppose the Iraqi government, enhance their own militias, or insist on self-rule and group rights. These entities will compete for recognition, revenues and resources within existing state borders, as well as access to external patronage. Yet, their very weakness also means that they will have to make deals with other non-state actors and larger official power brokers — the Iraqi government, the KRG and provincial administrations — to secure and administer their localities. The basis of these deals will largely be transactional and based on access to goods, services and salaries, at least in the short term.

Indeed, this hyper-fragmentation enhances the potential for local conflicts. Militias that control neighborhoods operate outside the rule of law and state institutions and can initiate violence at will. Violence has already erupted in former ISIS safe havens in northern Iraq among IRGC-backed PMFs, Sunni Arab tribes, Kurdish Peshmerga and other local militia forces. Deep divisions between PMFs and their rival political leaders risk militia clashes in Baghdad and outlying areas. In the neighborhood of Karrada, for instance — the site of an ISIS suicide bombing that killed nearly 300 on July 3, 2016 — a dozen PMF factions and militias are vying for authority.³⁸ Tensions also exist at a societal level, where distrust is palpable.

Yet, hyper-fragmentation also creates opportunities for pacts between groups that cross ethnic and sectarian lines. Barzani's Peshmerga, for instance, will be obliged to negotiate with Sunni Arabs in order to secure the KRG's extended border and oil resources. Negotiations between Baghdad and Erbil will also likely continue, amid ongoing tensions, to address financial and political challenges. Deals have also been made between the Iraqi government and Sunni Arab tribes to incorporate local forces into official Iraqi security institutions (and for salaries). Similarly, some of the localized militias in northern Iraq have been incorporated into Kurdish Peshmerga forces and will require ongoing pacts and patronage. The potential for negotiation will also depend on incentive structures and demographics in particular localities, access to resources, and external support that can enable or dissuade certain groups or encourage negotiation. One consequence of these localized and transactional agreements will be greater political entropy in Baghdad and across Iraq, particularly if longstanding issues of territorial borders and control over oil resources are not resolved among provincial, KRG and Iraqi-government authorities.

Thus, security and governance challenges after the Syrian war and the defeat of ISIS will be driven by the simultaneous need for the Iraqi government to enhance state institutions and to share authority with regions and localities. These challenges will be shaped not only by a potential Sunni-Shia or Kurdish-Arab conflict, but by conflicts within the three communities, influenced by profound distrust and competition. Political instability will also continue, reflecting the fissures between Iraqi populations and the government.

Foreign governments and international actors should recognize the hyper-fragmentation of the Iraqi state and the widening gap between juridical and de facto sovereignty that will assure state weakness for the near future. Any effort to stabilize the country should focus on enhancing state institutions at the national, regional and provincial levels and determining how the different component parts can live together. U.S. policy priorities should include:

• State sovereignty and state-to-state relations: Emphasize Iraqi state sovereignty and support leaders driven by Iraqi nationalism who seek to bridge ethnosectarian divides and engage in reform. This effort should include regular and frequent engagement at the executive level that openly supports the Abadi government (and any inclusive, Iraqi-nationalist successor) and affirms the U.S.-Iraqi strategic partnership. The emphasis on state sovereignty should also extend to Syria and the rest of the region to assuage allies. The United States should continue efforts to negotiate a ceasefire with key regional actors, including Russia, Turkey and Iran, with the overall aim of defeating ISIS and maintaining state institutions and Syria's territorial integrity.

• Territorial units, not ethnosectarian affiliations: Address Iraqi stability and governance as a territorial issue and not an ethnosectarian problem. Instead of appealing to distinct ethnic and religious groups, U.S. policy makers and strategists should focus on strengthening the institutional capabilities of the state, to include provincial administrations and the KRG, in coordination with federal authorities. This effort can also include training assistance to the ISF, local and federal police forces, and Peshmerga. Assistance to the KRG should continue to be channeled through and coordinated with the Iraqi government. The United States should also be aware of its "enabling complex," which can inhibit Kurdish leaders from negotiating with the Iraqi government.

• Humanitarian and reconstruction assistance: Assist the Iraqi government and United Nations in stabilizing and reconstructing areas liberated from ISIS so that IDPs and refugees can return to their homes as quickly and safely as possible. Assistance should also be provided to the KRG, in coordination with the Iraqi government and the United Nations, for Syrian refugees, particularly as a potential long-term or permanent population. These efforts are directly tied to conditions in Syria, which will have to be addressed when the war ends and stability returns to different localities over time, even in part.