Washington ? If hard-won security gains made against the Taliban over the past year can be sustained during the peak fighting season in Afghanistan this summer, the U.S. and its allies may find they have “turned a corner” by the end of this year, Defense Secretary Robert Gates said Thursday.

It was one of the more optimistic comments about the war’s outlook by Gates, who has overseen an escalation of U.S. fighting this year and is widely expected to retire in coming months.

The U.S. plans to begin pulling out some of its nearly 100,000 troops in Afghanistan in July. The stated U.S. and NATO goal is to have Afghan forces take the combat lead by the end of 2014.