WASHINGTON

Harold J. Greene, the twostar Army general who became the highest-ranking U.S. military officer to be killed in either of America’s post-9/11 wars, was an engineer who rose through the ranks as an expert in developing and fielding the Army’s war materiel. He was on his first deployment to a war zone.

Greene was killed Tuesday when a gunman believed to be an Afghan soldier opened fire at a military academy near Kabul. More than a dozen other coalition soldiers were wounded, including about eight Americans. It was among the bloodiest insider attacks of the war in Afghanistan.

In a 34-year career that began at Fort Polk, La., Greene, a native of upstate New York, earned a reputation as an inspiring leader with a sense of humility. He had been in Afghanistan since January, serving as deputy commander of a support command called the Combined Security Transition Command, in Kabul.