Since May 2019, U.S.-Iran tensions have heightened significantly, and evolved into conflict after U.S. military forces killed Qasem Soleimani, the commander of the Iran's Islamic Revolutionary Guard Corps-Quds Force (IRGC-QF) and one of Iran's most important military commanders, in a U.S. airstrike in Baghdad on 3 January 2020. The United States and Iran have appeared to be on the brink of additional hostilities since, as attacks by Iran-backed groups on bases in Iraq inhabited by U.S. forces have continued. This book details U.S. policy options on Iran, Iran's regional and defense policy, and Iran sanctions.