Pay no attention to the Shi'ite militias threatening to kill U.S. troops in Iraq. The elite Iranian forces backing those militias have been ordered not to attack the Americans.

That’s the conclusion of the latest U.S. intelligence assessment for Iraq. And it represents a stunning turnaround for Iran’s Quds Force, once considered America’s most dangerous foe in the region.

U.S. intelligence officials tell The Daily Beast that the apparent Iranian decision not to target American troops inside Iraq reflects Iran’s desire to strike a nuclear bargain with the United States and the rest of the international community before the current negotiations expire at the end of November.

“They are not going after Americans,” one senior U.S. intelligence official told The Daily Beast familiar with the recent assessments. “They want the nuclear talks to succeed and an incident between our guys and their guys would not be good for those talks.”

The Quds Force, named for the Arabic word for Jerusalem, are believed to have hundreds of troops in Iraq. As the primary arm of the Iranian state that supports allied terrorist organizations, their operatives worried Obama’s predecessor so much that the Treasury Department began sanctioning its members in 2007 for sabotaging the government of Iraq. The U.S. military accused the Quds Force of orchestrating cells of terrorists in Iraq. In 2012, Wired magazine dubbed Quds Force leader Qassem Suleimani the most dangerous person on the planet. In 2013, the New Yorker arrived at a similar conclusion, and claimed he has "directed Assad’s war in Syria.”

More recently, the Treasury Department has accused the Quds Force of international heroin trafficking and conducting terrorism and intelligence operations against the Afghanistan government. That’s why it’s so extraordinary that the Quds Force would be perceived to be laying off U.S. forces in Iraq.

But in some ways, the assessment is not surprising. Both Iran and the United States share a common enemy in the Islamic State of Iraq and al-Sham (ISIS). In late August, U.S. airpower and Iranian-backed militias broke the ISIS siege on the town of Amerli. Suleimani, the commander of the Quds Force, was photographed in Amerli, after the town was liberated from ISIS.

The latest assessments from the U.S. intelligence community also interpret Iran’s behavior in part as linked to the ongoing negotiations between Iran, the United States, the United Kingdom, France, Germany, Russia and China.

A U.S. intelligence official said the Quds Force behavior was the equivalent of a confidence building measure, a diplomatic term that refers to a concession offered to improve the atmosphere of negotiations. (Iran had already offered to play a more “active role” in the regional fight against ISIS, in exchange for nuclear concessions.)

The latest U.S. nuclear proposal to Iran would be favorable to the Islamic Republic and allow Iran to keep many of its declared centrifuges so long as they were disconnected from one another. Iran’s declared facilities in Qom and Natanz use a centrifuge process to enrich uranium into nuclear fuel.

The latest U.S. assessment also undercuts the public warnings from Iranian backed militias in Iraq that are doing much of the fighting now against ISIS.

Last month, the three largest Shiite militias told President Obama not to send ground troops into Iraq. But because the Quds Force is so instrumental in funding, training and in some cases providing strategic direction to these militias, it would suggest these public warnings were merely idle boasts.

To date, the Pentagon acknowledges that there are more than 1,600 U.S. forces inside Iraq, but these forces do not engage in combat missions, according to the Defense Department. Instead, the U.S. presence in Iraq is to advise Iraqi and Kurdish forces, assess the state of those forces and protect U.S. facilities inside Iraq.

Earlier this month in New York, Iran’s foreign minister Javad Zarif said the presence of foreign forces inside Iraq “creates domestic opposition and domestic resentment.” But in response to a question about the Shi'ite militias’ warnings against the United States, he also stressed that Iran did not support “anything that would complicate the situation” in Iraq..

The recent public warnings from groups like the Mahdi Army and the Asa’ib al-Haq were reminiscent of Iraq between 2006 and 2009. That’s when Shiite militias, working closely with Iran’s Quds Force, placed the sophisticated improvised bombs on routes traveled by U.S. forces. In the later years of the conflict, American forces captured what they said were dozens of Quds Force operatives working inside Iraq.

Exactly how long this informal Quds Force truce lasts is anyone’s guess. But Kimberly Kagan, the president of the Washington-based Institute for the Study of War and a one-time adviser to Gen. David Petraeus, cautioned that this alliance of convenience could break down quickly. “Without a doubt, Iranian backed elements have declared their intention many times in the past to attack the U.S. inside Iraq,” she said. “Whether or not those elements have immediate intentions to attack the United is irrelevant. They are declared enemies of the United States.”

That said, Kagan added that she believed “The Iranians do have a short term interest in being on their best behavior during these nuclear negotiations.” Those negotiations are set to expire at the end of November.