And now, in washington today, one man entered the arena. Chuck hagel, the purple heart recipient from the vietnam war, the former senator, nominated to be secretary of defense. His former colleagues... See More
And now, in washington today, one man entered the arena. Chuck hagel, the purple heart recipient from the vietnam war, the former senator, nominated to be secretary of defense. His former colleagues met him with a fuselage of critical questions today, and abc's chief washington correspondent jonathan karl takes us about the fiery day. Reporter: He's a vietnam veteran and former republican senator, but today chick hagel found himself and his judgment under attack by a fellow republican and vietnam vet. Were you correct or incorrect when you said that the surge would be -- the most dangerous foreign policy blunder in this country -- since vietnam. Were you correct or incorrect? Well, I'm not going to give you a yes or no answer on a lot of things today. Well, let the record show that you refused to answer that question. Reporter: Hagel eventually did answer, standing by his words on the iraq war, revealing something about the kind of defense secretary he hopes to be. I saw the consequences and the suffering and the horror of war. So -- I did question a surge. This going to be worth the sacrifice? We lost almost 1,200 dead americans during that surge. Now, was it required? Was it necessary? Reporter: Hagel would be the first defense secretary who saw combat as an enlisted soldier. As a poor kid from nebraska, he and his brother, tom, volunteered to serve in vietnam. The brothers served in the same infantry unit in 1968, both getting wounded, each crediting the other with saving their lives. I don't see the lens of every world event and whether we should use american power through the lens of vietnam. But it's part of me. Reporter: Hagel's service was praised -- I admire your service to your country. Reporter: But he was criticized for being soft on iran and too tough on israel. At one point, criticizing what he called thelobby. Today, he took that comment back. I should have used another term, and I'm sorry. And I regret it. Reporter: And hagel seemed to get confused about iran, which he called an elected, legitimate government, stating president obama's position on pursuit of nuclear weapons. Hagel is likely to be confirmed, but even supporters acknowledge he didn't have a familiarly strong performance today, saying that he still needs to learn more about the pentagon, telling the committee, quote, if confirmed, I intend to know a lot more than I do. Those were his exact words, diane. It was a bruising day. Thank you so much, jonathan karl.
This transcript has been automatically generated and may not be 100% accurate.