Former defense chief Hagel opens Pentagon's Vietnam exhibit

Former Defense Secretary Chuck Hagel returned to the Pentagon Tuesday to pay tribute to his fellow Vietnam veterans who he said fought in an unpopular war they didn't understand and returned to an ungrateful nation.

The two-time Purple Heart recipient formally opened the Defense Departments Vietnam war exhibit, which stretches along a segment of the third floor corridor and marks the 50th anniversary of the conflict.

Hagel said men and women who had nothing to do with the U.S. policy that launched the war, "came back to a country that was not only ungrateful, but their service was vilified. He and his brother Tom served in Vietnam in 1968. Hagel was Pentagon chief from 2013-2015.

The exhibit includes portions of two Huey helicopters as well as other historical combat displays.