Demonstrators support Iraqi Prime Minister Haider al-Abadi reforms in Baghdad mid-August. (Karim Kadim/AP)

Zalmay Khalilzad was the U.S. ambassador to Iraq from 2005 to 2007.

The reform campaign announced last month by Prime Minister Haider al-Abadi represents a potential turning point for Iraq. Indeed, the outcome of this campaign will shape the future of a country central to the global fight against the Islamic State and to the stabilization of the Middle East. The United States must focus on Iraq’s newest struggle and assist Abadi’s reform effort.

Abadi is rushing his reforms because of pressure from a nonsectarian movement, which includes many civil society groups, that has taken to the streets for several weeks. The role of Grand Ayatollah Ali Sistani, who encouraged Abadi to be courageous and embrace reform, has been critical. Abadi’s reforms include fighting corruption and establishing a meritocracy in government employment in place of party patronage and sectarianism. The protesters also want national reconciliation and reform of the judiciary, including the replacement of top judge Midhat al-Mahmoud, who was a key enabler of the unconstitutional actions by Abadi’s predecessor, Nouri al-Maliki.

Sectarianism has been a cancer on Iraqi politics. The last large-scale expression of nonsectarian politics came during the 2010 elections, when an improved security environment briefly reduced the potency of identity politics. But sectarianism surged again when security deteriorated after the U.S. military withdrawal. Today’s events offer a rare second chance for Iraq.

Abadi’s reform effort faces three key challenges:

First, it has divided the Shiites, producing a political confrontation that Sistani aide Ahmed al-Safi has described as an “existential battle.” The reforms are opposed by militia leaders, including the Badr Organization’s Hadi al-Amiri and Kataib Hezbollah’s Abu Mahdi al-Muhandis, as well as a number of political parties that support the political patronage system. Militia leaders have threatened reformers, targeting protesters with violence and kidnapping and even engaging in a deadly skirmish with security forces in Baghdad last week. They have also issued statements opposing national reconciliation in defiance of the prime minister and met with Mahmoud to express support for him.

Second, while the prime minister’s goals are laudable and ambitious, the means available to him to implement them are limited. Given lower oil prices, Abadi has far fewer financial resources than his predecessor. Complicating matters is the fact that, in the war against the Islamic State, he needs the support of the very militias opposed to his reforms. Many senior government officials hold their positions because of patronage and are unlikely to help his agenda succeed. And Abadi’s relations with the Kurds are strained by disputes over oil exports and the budget, among other issues. Abadi’s most important assets are support from Sistani and popular demands for reform.

Third, it appears that Iran wants the militias to dominate the Iraqi security sector and render it loyal to Tehran’s hard-liners. Abadi wants these militias and volunteer forces to be regulated and reorganized in a National Guard force under state control. It’s likely that Iran hopes the prime minister will fail and either simply abandon the reform program to work more closely with Iran or be replaced by someone who will side with the militias. Maliki began his first term as an independent leader, but as conditions changed and put his political survival at risk, he embraced Iran. Abadi’s reform agenda and Iran’s response to it have produced a nationalist Iraqi backlash against Iran. Sistani, Abadi and other reform leaders want good relations with Iran, but they resent Quds Force leader Maj. Gen. Qasem Soleimani’s effort to turn Iraq into a satellite state.

There is much at stake for Iraq in this struggle. The reform program is not comprehensive — it does not address the problems of the Kurdish region. Nevertheless, its success could lead to more effective governance, reconciliation and a reduction in sectarian tension. Sectarianism and discrimination against Sunnis have fueled extremism and terror in parts of the Sunni Arab community. Greater independence from Iran can also have a positive effect on Iraq’s regional relations and reduce Sunni Arab states’ incentives to support Sunni insurgents and terrorists. Greater emphasis on competence and the rule of law can reduce corruption and improve services for the Iraqi people — and even attract investment to Iraq.

The United States has an interest in the success of reform. To help tip the political balance of power in Abadi’s favor, policymakers should focus on understanding the nature of Iraq’s reform movement and identify ways to bolster and support it. Washington should also continue to provide robust military assistance. The U.S. effort to rebuild the Iraqi army is crucial to provide Abadi with loyal security forces and a strong formal chain of command. This security relationship and our operations against the Islamic State are vital for Abadi. Without them, Iran’s leverage grows.

We should also respond positively to Abadi’s appeal for help, and help him with implementing the reform agenda by providing technical advice to turn objectives into actionable plans and during the execution phase in areas such as fiscal policy, ministerial restructuring, tax reforms and electricity generation and distribution. We should also help Abadi refine the scope and pace of reform to make sure he doesn’t overreach.

Finally, this is a perfect time to redouble our diplomatic support by encouraging Iraq’s Sunni neighbors to constructively engage with Abadi. The reform campaign is evidence that he is moving away from the sectarian policies of his predecessor. The United States should emphasize to Iraq’s neighbors that successful reforms can help with national reconciliation and rebalance Iraq’s relations with its neighbors, positively affecting the broader region.

This struggle for political, economic and national security reform in Iraq is likely to be a long one, and success is not inevitable. Prime Minister Abadi faces major domestic and Iranian pressures, and he needs our help to make progress. We need to act quickly.