Prior to the initial U.S.-led invasion of Iraq, there was furious and sustained U.S. and British diplomacy with Iran. At the time, British foreign secretary Jack Straw elicited a promise from Iranian foreign minister Kamal Kharrazi that Iran would not interfere in Iraq. Separately, Mohammad Javad Zarif, at the time Iran’s ambassador to the United Nations and now Iran’s foreign minister, told Zalmay Khalilzad, the National Security Council official responsible for Iraq, the same thing.

Just weeks later, however, according to Iranian journalists like Ali Reza Nourizadeh, a writer close to former president Mohammad Khatami and aides like Hassan Rouhani, the Islamic Revolutionary Guard Corps (IRGC) infiltrated 2,000 fighters, militiamen, and Qods Force personnel into Iraq. The White House acknowledged concerns over the infiltration and took action. Within six months of the start of major combat in Iraq, coalition forces had detained more than a hundred Iranians in Iraq. Simply put, Iran looks at diplomacy as an asymmetric warfare strategy to distract adversaries while they establish facts on the ground.

A major theme of my recent book was that while the U.S. military constantly examines its mistakes in order to learn from them, the State Department does not engage in lessons-learned exercises. Secretary of State John Kerry is absolutely right that the United States and Iran have a shared interest in Iraq. Then again, firefighters and arsonists have a shared interest in fires.

Let us hope that President Obama understands that it is a lot easier to bless Iran’s entrance into Iraq than achieve its exit. If he has any doubts, he can just as the Lebanese, who have been struggling against an Iranian-created proxy group if not IRGC advisors for almost 32 years or, if charitable, for 14 years after Israel’s withdrawal from southern Lebanon.