(CNN) - Days before Chuck Hagel sits down for Senate hearings on his nomination to be secretary of defense, the former senator received vocal support from two retired generals on Sunday.
Retired U.S. Army Gen. Stanley McChrystal and former CIA director and retired U.S. Air Force Gen. Michael Hayden both said on CNN's "State of the Union" that they expect Hagel to work well as the Defense Department chief.
Hagel would be the first defense secretary who enlisted in the military. He volunteered to join the Army and ended up serving a yearlong tour in Vietnam in 1968 during the Tet Offensive, considered the most violent period in that war. Because of a clerical error, he served side by side with his younger brother.
He earned two Purple Hearts, one of which was for saving his brother's life. The second Purple Heart was for injuries from shrapnel he took in the chest while on patrol with his brother; his brother saved his life by patching up the wound.
Asked Sunday how Hagel's experience might affect his role as head of the Defense Department, Hayden said it could be a "tremendous attribute."
"I think it would be fine," Hayden told CNN's chief political correspondent Candy Crowley. "I know Sen. Hagel. He was on my oversight committee when I was in the intelligence community. He was a member - and this is not a universal condition - he was a member that you could talk to, have an honest dialogue - not necessarily disagree, but on a personal base have a candid exchange of views. You could always speak with him. And frankly, given my time in uniform, that's a tremendous attribute."
"So I actually think this will work out well," he added.
McChrystal said he doesn't think military service is a "perquisite" for the job but argued it can be "very helpful."
"Then of course he'll build relationships as he goes. He has already got a lot of credibility," he said. "I don't think it will be a problem."
Their comments come after days after retired Gen. Wesley Clark, a former Democratic presidential candidate, also praised Hagel as a potential secretary of defense.
Hagel, a Republican, has already taken heat for a variety of past statements and positions. Critics argue he's not a strong supporter of Israel and appears too conciliatory toward enemies.
In his 2006 biography, Hagel said he's not a "pacifist" but a "hard-edged realist."
"I understand the world as it is - but war is a terrible thing. There's no glory, only suffering," he is quoted as saying in the book.
His hearings, widely expected to be contentious, are set to begin Thursday.
- CNN's Mike Mount contributed to this report.
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