Archive images of U.S. Marine General John Allen, who led the NATO forces in Afghanistan and was caught up in the scandal that forced CIA CIA chief David Petraeus to resign.

Allen said on Tuesday he will retire and forgo his nomination to become NATO’s supreme allied commander because of his wife’s health.

The decision ends the career of one of the U.S. military's most well-known leaders, who until Feb. 10 spent 19 months in Afghanistan trying to help wind down America's longest war and strengthen Afghanistan's military to fight insurgency.