Within Iraq, the presence of paramilitaries and militias has long had a corrosive impact on security. My major criticism of former Prime Minister Nouri al-Maliki, for example, was not that he sought to arrest Vice President Tariq al-Hashemi for running death squads—Hashemi was most certainly guilty—but rather that the prosecution was selective: Maliki should have gone after some of the same Shi‘ite groups with the same zeal, his willingness to have once done so in Basra notwithstanding.

With the explosion of the Islamic State (ISIS) onto the scene—and the seeming disintegration of large parts of the Iraqi army—Grand Ayatollah Ali Sistani issued a call for volunteers to defend Iraq and the holy Shi’ite shrines. While the reason for the weakness of the Iraqi military deserves serious consideration by Iraqi politicians and American trainers alike, these volunteers buttressed the Iraqi army at a time of great need. Ramadi, the capital of Al Anbar, and the shrine city of Karbala are only 70 miles apart. With ISIS assurgent, Karbalais had real fear that the group too radical even for al-Qaeda might seek to attack their city and loot and destroy its holy shrines, as Saddam, the Ottomans, and the Saudis did at various times through history.

Staying in Karbala this past week, I stayed in the same compound as some volunteers training to fight ISIS also resided. I saw several, fresh off the bus, ranging from teens to grey beards. One morning, awaiting my ride to the Shrine of Imam Hussein, I saw several groups of more seasoned volunteers march in formation as they went to eat in the same communal dining hall from which I had just emerged. They did not seem like zealots, but rather as those who felt they needed to answer the call to defend their families and communities. I certainly wish them the best of luck in their fight against ISIS.

What I worry about, however, and what many locals inside Karbala also seem concerned about is what will happen when the fight ends and the volunteers return. Already, Shi’ite militias pose a real challenge to Iraq. Groups like the Shi’ite Asa’ib Ahl al-Haq, which recently reiterated its fealty to Iranian Supreme Leader Ali Khamenei and not Iraq’s elected government, represent as much a threat to Iraq’s recovery as does the underground Baath Party, if not the ISIS itself.

It is one thing if volunteers quietly return from the towns and villages from where they came, and resume whatever job—if any—they were doing before they answer the call. The likelihood of this, however, is low. Many will expect reward for their sacrifice, and seek to transform their efforts into power.

There are many examples of this through recent history. In Iran, those who joined the Islamic Revolutionary Guard Corps refused to return to their barracks upon the end of the Iran-Iraq War. They moved into the civilian economy and increasingly flexed their muscles to pressure the Iranian government and remain autonomous.

Likewise, in Iraqi Kurdistan, the peshmerga who fought against Saddam Hussein expected to be rewarded with jobs and patronage when the Iraqi government withdrew from Iraqi Kurdistan in 1991. The characteristics that made a good mountain warrior and those that made a good manager are two very different things. Much of the government dysfunction and corruption that has blighted Iraqi Kurdistan in the more than two decades since the establishment of the Kurdistan Regional Government has roots in this problem. Indeed, younger, capable officials like Barham Salih have long faced obstacles to their career simply because they did not fight in the mountains.

Back to Karbala and, by extension, southern Iraq: By all accounts, Haider al-Abadi is off to a good start in Baghdad, though the problems he and Iraq face are daunting. The fight against ISIS might be the most immediate challenge Iraqis face, but it is not too late to start planning for the next one: not only the reconstruction of those areas scarred by battle and the reintegration of Sunnis into the Iraqi government, but also the status of the Shi’ite volunteers once the fight is over.