What is Iran doing in Iraq?

After the U.S. withdrew its troops from Iraq in 2011, Baghdad became increasingly dependent on Tehran on various avenues, from trade to security, which raised Iran’s global profile. Iran established a Shia corridor stretching from Tehran through Baghdad and Damascus to southern Lebanon where Hezbollah operates. But Iran’s strategic calculations came under threat when the Islamic State made inroads into north-western Iraq.

The IS, which is anti-Shia, captured Mosul, Iraq’s second largest city, in June 2014 and was marching towards Baghdad. Had the IS taken over Baghdad, Iran would not only have lost a friendly regime, but also felt the heat of an anti-Shia jihadist group closer to its borders. Its focus immediately turned to building Shia militia groups, along with the Iraqi government, to fight the IS in Iraq. These groups, known as Popular Mobilisation Unites, or Al-Hashd al-Shaabi, have played a major role in the liberation of Iraqi cities, such as Ramadi, Fallujah and Mosul, from IS rule.

How did Iran gain entry?

If there’s one country in West Asia that benefited from the United States’ 2003 invasion of Iraq, it was Iran. For the Islamic Republic, which fought an eight-year-long war with Iraq in 1980-88, Saddam Hussein’s regime remained a security concern. In the pre-Iraq war scenario, Syria was the only stable ally of Iran, but both countries were separated by a hostile Iraq. Iran had started building influence inside Iraq through its cross-border cultural and religious links, but even that had limitations as the Saddam regime turned against Iraq’s Shias in the aftermath of the first Gulf War. The U.S.-led invasion removed this hostile regime and practically opened the gates of Iraq to an ambitious Iran ruled by Shia clergy.

Iraq is a Shia-majority country, which Saddam Hussein’s secular Ba’ath party ruled for decades with an iron fist. When the post-Saddam Iraq held the country’s first free elections in 2005, Shia parties, most of which had had long-standing relations with Iran, rose to power. Ever since, Iran’s influence in Iraq has only grown — first as a counterforce to the American occupation and then as a security provider to the Iraqi government.

Why is Iraq crucial for Iran?

Iran doesn’t have many allies in a region which is dominated by hostile Sunni powers. Iran counters this asymmetry in geopolitical leverage by building influence with non-state actors. Hezbollah, the Lebanese Shia militia, is one of its greatest strategic assets in West Asia. With a friendly government in Baghdad, Iran not only got a buffer between itself and the Sunni bloc, but also direct access to Syria, which has been a conduit for Iranian supplies for Hezbollah. But in the immediate aftermath of the Iraq war, it was not clear whether Tehran would be able to successfully cultivate dominance in Iraq. The presence of over 1,00,000 U.S. soldiers posed a direct challenge to Iran’s ambitions.

The George Bush administration had also lumped Iran with Iraq and North Korea as the “axis of evil” and had threatened it with military action. Against that context, the Iranian strategy was to make the U.S. occupation costly. It supported Shia militias in Iraq’s south, while Sunni terrorist groups such as al-Qaeda in Iraq attacked both Shias and U.S. soldiers in the north. The Iranian strategy was partly successful as the U.S. eventually withdrew most of its troops from Iraq, but only after the invasion and the subsequent sectarian civil war ravaged the country.

Will Iran pull back?

Now that the Iraqi government has declared the defeat of the IS, will Iran withdraw its militias and let Baghdad run the country on its own? Given Iran’s strategic ambitions and the recent history of its dominance in Iraq, it’s unlikely to happen. On the contrary, at a time when the U.S. and the Sunni monarchies in the Gulf are teaming up against Iran, Tehran would try to deepen its relations with countries such as Iraq and Syria and non-state militias such as Hezbollah and Hashd al-Shaabi. Al-Shaabi, comprising some 40 militia groups that are loyal to Tehran, could translate its military influence into political clout, which will be crucial as Iraq goes to the polls next year. This explains why the Iraqi political leadership hardly expresses any views critical of Iran.