Insider attacks, those perpetrated by Afghan soldiers being trained by U.S. troops, have been one of the biggest obstacles in the way of a smooth transition of U.S. troops out of the war-torn country over the next two years, but November may have marked a turning point. Last month was the first time in 2012 that no Americans were killed by an insider attack, according to Military Times.

Between January and October, 35 American troops were killed by Afghan soldiers, which was about 10 percent of the total who died in combat this year. However, the military implemented new practices to identify potential threats, such as singling out soldiers who have recently traveled to Pakistan, and it seems to have made a difference.

"There have been significantly fewer [insider attacks] over the last several months than before," a senior defense official told the publication. "However, I would be very loathe to say –  in fact I would not say  – it’s a problem that’s been solved. It’s a problem we continue to address."

Still, it's hard to deny that the November milestone is an important one, as the United States works toward its goal of exiting Afghanistan by 2014.