Recent events indicate that insurgencies in both countries could eventually merge into one contiguous conflict zone, with profound consequences for Iraqi stability.
In the past week, the conflict in Syria has spilled over into Iraq in unprecedented ways. On March 2, the Yarubiyah border crossing in Syria became the scene of heavy fighting, spurring regime troops defending the post to retreat into Iraq and prompting Iraqi security forces to fire on Free Syrian Army (FSA) rebels. Two days later, a convoy of Syrian military personnel was ambushed in western Iraq as they were being repatriated, resulting in fifty-one Syrian and Iraqi deaths. Whether the attack was launched by Syrian fighters entering Iraq or Iraq-based fighters sympathizing with the rebels, the implications are clear: the border is increasingly no obstacle to the war's spread. At a time when Iraq's own sectarian tensions are boiling, the last thing the country needs is to become an active participant in the increasingly sectarian Syrian conflict.
BACKGROUND
The Shiite-led Iraqi government has long sought a negotiated settlement in Syria that would deny the Sunni-led rebels a full victory, aligning Baghdad closely with the positions of other pro-Assad states such as Iran and Russia. Iraq has provided the regime with significant indirect support to bolster its flagging military power, and Iraqi roads and airspace have been used to move armaments from Iran to Syria. Baghdad has also overlooked the cross-border movement of Iraqi Shiite militiamen fighting for the regime alongside Lebanese Hezbollah volunteers (e.g., with the Abu Fadl al-Abbas Brigade near Sayyeda Zainab, Syria).
At the same time, Iraqi officials have condemned foreign support for the Syrian rebels. On February 22, Transport Minister (and leader of the Shiite Badr Organization) Hadi al-Ameri accused Turkey and Qatar of arming Jabhat al-Nusra, a rebel brigade affiliated with al-Qaeda in Iraq. In his view, any such provision of "money and weapons to al-Qaeda [in Syria] is a declaration of armed action against Iraq." And on February 27, Prime Minister Nouri al-Maliki warned, "If the opposition is victorious, there will be a civil war in Lebanon, divisions in Jordan, and a sectarian war in Iraq."
In addition to pervasive fear of backlash from Sunni-led states against Shiite-led Iraq, Maliki's dark outlook on the Syrian opposition is colored by escalating political tensions with Sunni Arabs at home. Pro-FSA banners and chants have been prominent at many anti-Maliki protests in Anbar province, and the Iraqi government has long recognized the sympathetic ties and smuggler networks that exist between Syrians and Iraqis of the Euphrates River Valley and the Jazirah desert.
BORDER VIOLENCE
Beginning in July 2012, the Iraqi army deployed additional resources to support outposts on the Syrian border. In Anbar, units of the 28th and 29th army brigades and several commando companies were sent to patrol bases near the frontier, while elements of the 38th brigade were moved from the southern Dhi Qar province to the Rabiyah border crossing (the Iraqi side of Syria's Yarubiyah crossing) in the northwestern Ninawa province. In addition to defending border towns from violent spillover, these deployments were intended to constrain cross-border cooperation between Iraqi tribes and Syrian rebels as well as facilitate military aid shipments to the regime in Damascus.
Recent events in the Rabiyah area illustrate how the border situation is becoming more volatile, with Iraqi army forces entering into more frequent armed clashes with Syrian rebels. The predominately Shiite troops in Rabiyah are relatively new to the area and have been repeatedly targeted by al-Qaeda in Iraq, including a suicide car bombing in November that wounded six. In addition, seven Iraqi soldiers have been killed and twenty-two wounded in the past year by cross-border gunfire or clashes with smugglers. Most recently, two soldiers were killed by cross-border gunfire on March 2. That same day, mortar rounds from Syria struck Iraqi positions, and Iraqi snipers and mortar crews fired at FSA rebels who approached the Rabiyah crossing after Syrian government troops sought refuge there. The previous day, a large surface-to-surface artillery rocket fired from Syria -- described by Iraqi spokesmen as a "Scud" with a "half-ton warhead" -- left a three-meter-deep crater to the east of Rabiyah, less than forty miles from Iraq's third-most-populous city, Mosul.
Monday's incident was particularly shocking -- the Syrian troops who had entered Iraq on March 2 were sent to the Walid crossing in western Anbar for repatriation, but their convoy was ambushed with roadside bombs, mortar rounds, and small-arms fire shortly before it reached the Iraqi post. Forty-two Syrian soldiers and nine Iraqi escorts were reportedly killed.
The convoy attack had a number of precedents in the area. The Rutbah district of Anbar province is a trucking hub on the roads to Syria and Jordan, and al-Qaeda in Iraq has been resurgent there since 2010. The uncontrolled western desert area has been the scene of numerous gruesome vignettes, most notably the July 2011 discovery of three prominent sheikhs beheaded and booby-trapped to prevent their burial, and the September 2011 massacre of twenty-one Shiite pilgrims pulled off a bus in Nukhayb. The prearranged nature of the March 4 ambush may indicate that Syrian convoys are a regular occurrence in the area, and/or that the attackers were forewarned by local contacts in the civilian population or security forces.
IMPLICATIONS FOR U.S. POLICY
Clearly, a merger of the Syrian and Iraqi insurgencies would be bad for Iraq, Syria, and U.S. interests. Washington must engage Baghdad to prevent Syria's war from seeping further into Iraq, which could rejuvenate the moribund Sunni Arab insurgency. In particular, it should vigorously remind Baghdad of the destabilizing consequences if government forces or Shiite groups overreact, especially if they take action against domestic Sunni communities in an effort to root out Iraqi and Syrian jihadists.
Washington should also push back on Baghdad's emerging narrative that Sunni protests in Iraq are simply "spillover from Syria," as National Security Advisor Falih al-Fayadh intimated on February 25. His statement that "the divisiveness in Syria might affect the unity of Iraq" conceals the fact that Baghdad's own failure to support sectarian reconciliation since 2009 has been a key driver of Sunni unrest and should be corrected. The current wave of "preventive" arrests in and around Sunni portions of the capital only increases the risk of the spillover Fayadh warned against. The Sunni community would be reassured if Baghdad dealt firmly with new Shiite vigilante groups such as the al-Mukhtar Army, which seeks to exploit growing sectarian dread in the Shiite community by threatening to purge Sunnis from mixed neighborhoods.
A truly explosive moment could occur after the Assad regime's ouster, when Iraqi Sunni exhilaration may collide headlong with a government crackdown in Baghdad and surrounding areas. If that moment comes, U.S. leaders and diplomats must be ready to dedicate focused effort on the Iraqi government at a time when attention will be dominated by events in Syria. In that scenario, Washington would also need to press factions in post-Assad Syria not to meddle in Iraq.
Michael Knights is a Boston-based Lafer fellow with The Washington Institute.