The U.S. effort to protect the sea lanes in the straits of Hormuz as the Iranian backed Houthi rebels advance into the southern port city of Aden in Yemen. This involves support of Saudi airstrikes in Yemen and control of airspace over Yemen. In Iraq the U.S. makes airstrikes to support Iranian backed Shiite militias near Tikrit. The lack of a coherent policy and years of inaction by the Obama administration in the Middle East leads the U.S. into a situation where it is drawn into airstrikes on both sides of the Middle Eastern sectarian Sunni-Shiite conflict.