DOVER, DE (AP) – The body of a two-star general killed in an Afghan “insider attack” arrived today at Dover Air Force Base. Maj. Gen. Harold Greene is the highest-ranked U.S. officer to be slain in combat since 1970 during the Vietnam War. Greene, a 34-year U.S. Army veteran, also is the highest-ranked American officer killed in combat in the wars in Afghanistan and Iraq. Investigators are trying to determine why and how a man dressed in an Afghan army uniform opened fire Tuesday at a military compound. Greene was a graduate of the U.S. Army War College in Carlisle, Cumberland County.