Baghdad-sanctioned Shiite militiamen allied with Iran, including fighters who want to push U.S. troops out, have gained control of many of the Sunni territories in Iraq they helped liberate from the Islamic State (ISIS/ISIL).

Their presence is fueling local resentment that could lead to an Islamic State (ISIS/ISIL) revival, the Washington Post (WaPo) reported Wednesday.

An umbrella organization for predominantly Iranian-backed Shiite known as the Popular Mobilization Forces/Units and Hashd al-Shaabi is “enjoying unprecedented military and political power in Iraq” after it won nearly a third of the seats in parliament during the recent elections, the Post noted, adding:

With major combat [against Sunni ISIS] over, the militias — some with roots dating back to the Saddam Hussein era, others that emerged to fight U.S. occupation after 2003 and yet others that formed in 2014 to fight the Islamic State — are setting their sights on political and economic goals. They are fanned out across Iraq’s Sunni heartland, including the provinces of Anbar, Salahuddin and Nineveh, home to Iraq’s most-populous Sunni city of Mosul. In Sunni towns, the militias have established political and recruitment offices and operate checkpoints along major roads (and even smaller interior pathways), levying taxes on truckers moving oil, household goods and food.

PMF fighters, estimated to number up to 150,000 in Iraq, helped the United States and Iraqi security forces annihilate the ISIS territorial caliphate in Iraq, earning the praise of high-ranking American military officials.

Although the Pentagon’s office of the inspector general (OIG) and independent assessments have deemed the Shitte organization a significant threat to U.S. troops, fighting the Shiite militiamen is not part of the American mission in Iraq, Breitbart News learned from the U.S. Department of Defense (DOD) late last year. The Pentagon has the legal authority to fight ISIS because it was once a wing of al-Qaeda; the active Authorization for the Use of Military Force (AUMF) enacted after the September 11, 2001, terrorist attacks permit military action against al-Qaeda, but not Iran.

In the wake of President Donald Trump’s surprise holiday visit to Iraq last month, PMF factions Kata’ib Hezbollah (KH) and Asa’ib Ahl al-Haq (AAH), considered terrorists by several U.S. officials, have renewed threats against America’s military presence in Iraq, vowing to push the United States armed forces out of the country.

AAH fighters have been linked to thousands of attacks against U.S. troops between 2006 and 2011.

Citing several Iraqi and U.S. officials, WaPo reports that the Shiite fighters are engaging in “mafia-like practices,” extorting protection money from both large and small businesses in Sunni areas as well as “shaking down motorists at checkpoints” to allow locals to pass.

“The militias are also deciding which Sunni families are allowed to return to their homes following battles against the Islamic State, say analysts who study the groups,” the Post adds. “In several towns, militia leaders have compelled local councils to invalidate the property rights of Sunnis on the grounds that they supported the Islamic State. The practice has led to major demographic changes in traditionally mixed Sunni-Shiite areas such as Hilla and Diyala.”

Acknowledging that about 1.8 million displaced Sunnis are still living in overcrowded camps and shelters, Hisham al-Hashimi, a security analyst who advises Iraq’s government and foreign aid agencies, indicated to the Post that efforts to prevent their return home fuel potential radicalization.

The militias “are an obstacle to the stability of these areas because they are banning the return of internally displaced people,” he told WaPo.

A Baghdad-based U.S. official told the Post on condition of anonymity that Shiite militia control over Sunni territory “will surely prompt some to seek common cause with the Sunni militants of the Islamic State.”

PMF militias are moving fighters into neighboring Syria to help Iran support Russian-backed dictator Bashar al-Assad, the Post pointed out.

The fall of the ISIS territorial caliphate in Iraq has presented Iran with the ability to finally establish its long-time desired “Shiite crescent” sphere of influence — a single land route that binds together territory held by several Islamic Republic allies, including Hezbollah in Lebanon, the Assad dictatorship in Syria, and the Iranian-influenced government of Iraq.

U.S. President Donald Trump’s administration has pledged to combat Iran’s influence in the Middle East. Trump’s Secretary of State Mike Pompeo traveled to the region this week to sustain pressure on the Islamic Republic. The Trump administration has announced plans to withdraw American troops from Syria but has said U.S. service members will remain in neighboring Iraq.

Baghdad legalized the PMF as a component of Iraqi security forces. The Pentagon claims it only provides support to PMF fighters vetted for affiliation to U.S.-designated state-sponsor of terrorism Iran, as mandated by law.

Lt. Gen. Kenneth McKenzie Jr. — tapped to command American troops in the Middle East and Afghanistan as chief of U.S. Central Command (CENTCOM) — recently conceded that not all PMF factions — namely KH and AAH— are only nominally under Baghdad’s control.

“It is no secret that the most powerful militias are not loyal to Iraq’s religious or civilian authorities,” an unnamed commander with the U.S.-backed Counterterrorism Service in Iraq told the Post. “They will put Iran’s interests first.”

Currently, Iraqi PM Abdul Mahdi is considering a draft proposal that would double the annual budget of the PMF to $2 billion, putting the militiamen’s salaries on the same scale as those of the Iraqi police and military, the Post reported.

PMF-linked lawmakers have also nominated Shite militia leader Falih Alfayyadh as interior minister.