Green-On-Blue Attack
Afghan National Army (ANA) soldiers keep watch at the military training academy where a U.S. major general was killed in a green-on-blue attack. Reuters

The killing Tuesday of a U.S. major general, believed to be at the hands of an Afghan soldier, marks the third instance of so-called “green-on-blue” attacks in Afghanistan in 2014. Such insider attacks have seen a sharp decline since the 44 committed in 2012, which accounted for 15 percent of all coalition deaths in Afghanistan that year.

A “green-on-blue” attack is when an Afghan policeman or soldier fires on coalition forces in Afghanistan. In Tuesday’s incident, the Department of Defense said a man wearing an Afghan military uniform opened fire on coalition forces visiting a military training facility in Kabul, killing the major general and wounding 14 others. U.S. Maj. Gen. Harold Greene was widely reported to be the name of the officer. The Pentagon didn't publicly idenfify him earlier because his family wasn't yet notified, Pentagon spokesman Rear Adm. John Kirby said.

Part of the reason green-on-blue attacks have subsided since 2012 is because security measures were put in place to prevent such incidents following the spike (there were only two green-on-blue attacks in 2008, five in 2008 and 2009, and 16 in 2011, according to a tally compiled by the Long War Journal). Among the changes to security were “guardian angels,” or NATO soldiers who watch over NATO and Afghan troops. Then-U.S. Defense Secretary Leon Panetta announced the plan in August 2012, according to Foreign Policy.

The green-on-blue attacks also declined because there were fewer U.S. troops to target. At the beginning of the year, there were 32,000 soldiers in Afghanistan, down from 101,000 in June 2011, according to The Hill. President Barack Obama’s timetable for a drawdown of troops in Afghanistan would have about 10,000 troops by the end of the year, with a complete withdrawal by 2016, the New York Times reported in May.

“The long lull in attacks … is due in large part to the ongoing drawdown in coalition personnel, which has greatly reduced partnering with Afghan forces, as well as enhanced security measures such as the use of ‘guardian angels’ during joint operations,” according to the Long War Journal.