A pair of former Georgia U.S. senators backed Secretary of Defense nominee Chuck Hagel at a contentious confirmation hearing on Thursday. But the two currently in office remain publicly undecided, and Republican Sen. Saxby Chambliss delivered some skeptical questioning on Iran.

Former Georgia Democratic Sens. Sam Nunn and Max Cleland attended Thursday’s hearing before the Senate Armed Services Committee. Cleland, who declined comment, has been working behind the scenes to help his former colleague and fellow Vietnam War veteran. Hagel was a two-term Republican senator from Nebraska.

Nunn, a former Armed Services chairman, introduced Hagel along with former committee chairman John Warner, a Virginia Republican. Nunn hailed Hagel’s work on nuclear non-proliferation and cast him as a solid choice.

“From our service together on the Defense Policy Board, I know that Chuck has a very clear world view, and that it aligns with the mainstream of U.S. foreign and defense policy,” Nunn said. “Chuck Hagel believes that we must build and preserve American strength as a force for good in the world. He realizes that protecting our interests requires strong allies and friends and strong American leadership.”

Chambliss said he and Hagel were friends who served together on the Senate Intelligence Committee but added, “you cast some votes that I questioned.”

Chambliss questioned Hagel’s views on Iran, which are controversial among Republicans. He read passages from Hagel’s book in which the former senator signaled far more willingness for diplomacy than force.

“If your position is truly prevention and not containment (of a nuclear Iran), what is the red line?” Chambliss asked. “We know there are some things happening over there right now that are very serious, so how far do we go? Do you still advocate direct negotiations with Iran? … We’ve never negotiated with a terrorist state.”

Hagel said he did not want to publicly discuss “red lines,” and that he would defer to the president on that subject. On engaging diplomatically with Iran, Hagel said: “I think we’re always on higher ground … if we have tried and we have gone through every possibility to resolve this in a responsible peaceful way, rather than going to war.”

Hagel told Chambliss that Iran has an “elected, legitimate government, whether we agree or not.”

Hagel tripped up during the Chambliss exchange by saying “I support the president’s strong position on containment.” President Barack Obama’s position is to prevent Iran from getting a nuclear weapon, not contain it. A few minutes later, when presented with a note from an aide, Hagel said the U.S. does not have a position on containment. Then Sen. Carl Levin, D-Mich., the committee chairman, stepped in to correct Hagel again: “We do have a position on containment, and that is we do not favor containment.”