Summary: The two top-ranking leaders of al-Qaida in Iraq, Abu Omar al-Baghdadi and Abu Ayyub al-Masri, were killed in a joint U.S.-Iraqi operation on Sunday, April 18, 2010, in what Vice President Joe Biden called a “potentially devastating blow” to the terrorist operation. … One-year retrospective: One year ago today, on April 21, 2009, Aubrey Immelman reported that the U.S. Senate confirmed President Barack Obama’s pick for U.S. ambassador to Iraq, Christopher Hill, after debate over whether he mismanaged international disarmament talks with North Korea. Meanwhile, suspected militants shelled Baghdad’s protected Green Zone in the first such bombardment in more than three months.