In an attempt to find common ground against ISIS and push for a nuclear deal, President Barack Obama secretly wrote to Iran’s Supreme Leader Ayatollah Ali Khamenei in the middle of October. Obama reportedly wrote that U.S. cooperation with Iran on ISIS was contingent on Iran working out a deal with global powers on its nuclear program by the Nov. 24 deadline. This would be the fourth time Obama has written to Iran’s religious leader since he took office.

Leslie Gelb wrote at The Daily Beast two weeks ago that the only way to defeat ISIS would be working with Iran and Syria. Already though, Washington has tacitly worked with Tehran in Iraq to beat back the so-called Islamic State. Jacob Siegel reported in September that Iran’s chief military strategist was in Iraq overseeing a group that was spearheading a U.S.-backed operation in Amerli. Iran also told its elite troops in Iraq to leave American forces alone as they both worked against ISIS.

News of Obama’s letter to Khamenei is sure to inflame Republicans on Capitol Hill. Eli Lake reports that Republicans plan to dig into the administration’s talks with Iran over nuclear weapons. “There is going to be real scrutiny from the House and Senate in what’s taken place on the entire Obama administration’s tenure dealing with the Iranians,” said Rep. Devin Nunes, the presumptive chairman of the House Intelligence Committee.