Some national Jewish leaders, deeply worried and upset over the nomination of former Nebraska Sen. Chuck Hagel as secretary of defense, are in a quandary about whether or not to publicly speak out against his confirmation.

Their concern is that, especially for a Republican, he has been less than warm toward Israel and that despite — or because of — his experience as an infantryman in the Vietnam War, he is particularly hesitant to use military force and has favored diplomatic negotiations with Iran, Hezbollah and Hamas.

Mainstream Jewish groups generally don’t contest presidential appointments and the leaders are not at all certain that their complaints could have an impact on the Senate vote. They also worry that if Hagel is confirmed, he could be less than responsive to their future input, and their already tenuous relationship with President Barack Obama could be weakened. So why go to the wall if there is a good chance of losing?

Because some believe it is a matter of principle and they should voice their reservations anyway. But it appears they are softening their rhetoric now that Obama’s decision has been announced.

Several pro-Israel groups had been very vocal in warning against the Hagel appointment on grounds that he is anti-Israel, noting that he criticized the official pro-Israel lobby AIPAC and refused to sign on to some resolutions supportive of the Jewish state.

Hagel, responding to such criticism, told the Lincoln (Neb.) Star Journal this week that there is “not one shred of evidence that I’m anti-Israel, not one (Senate) vote that matters that hurt Israel.”

A far more substantive concern, and one that avoids making Israel a front-and-center issue, is that Hagel’s views on Iran differ considerably from Obama’s public statements on the issue.

The president has been clear in saying he refuses to accept the containment argument — that is the notion that it is too late to stop Iran from achieving nuclear capabilities to build arms so we should concentrate on containing it. But that’s something Hagel has indicated he can live with. And while Obama has kept the possibility of a military attack by the U.S. on the table, Hagel is opposed, insisting that a resolution can be reached through negotiations, which he also calls for in dealing with the terror groups in Gaza and Lebanon.

Republican Jewish leaders no doubt are saying “I told you so” to the fact that Obama, who they view as insufficiently supportive of Jerusalem, chose Hagel to run the Pentagon at a time when much of the Mideast is in chaos and Iran appears to be closing in on developing nuclear arms.

Defenders of the president insist he will make the critical decisions and that he likes and trusts Hagel, who will offer a fresh approach at the Pentagon, which needs to make deep cuts in military spending.

AIPAC has not taken a stand and likely will not. The Anti-Defamation League’s national director, Abraham Foxman, who had opposed the nomination, said in a statement this week: “Sen. Hagel would not have been my first choice, but I respect the president’s prerogative.”

The American Jewish Committee went further, stating that Hagel’s “statements and actions on a range of core U.S. national security priorities raise questions that require clarification,” including “the special nature of the U.S.-Israel relationship and Israel’s quest for peace and security.”

Several dovish Jewish groups, including J Street, Americans for Peace Now and the Israel Policy Forum, endorsed the nomination.

With Israeli Prime Minister Netanyahu almost certain to retain his post after the Jan. 22 national elections, and with a re-elected Obama choosing Sen. John Kerry as his nominee for secretary of state and Hagel for the Pentagon, it appears that U.S.-Israel relations are not going to get any smoother for now.