In this talk, General Mattis applies his extensive national security and policy experience to current US-Iranian diplomacy. He centers his remarks on the Joint Comprehensive Plan of Action, commonly known as the Iran nuclear agreement, which he views as a serious misstep in US policy. He explains the political and historical context of the deal, analyzes how the Iranian regime is modifying its behavior in response, and how US policy makers can correct course. Although Mattis is measured in his analysis, he draws a stark conclusion: “the Iranian regime is the single most enduring threat to stability and peace in the Middle East.”