After all the thunder and lightning signifying nothing but more Republican obstructionism, former Sen. Chuck Hagel has taken over at the Pentagon, vowing a realistic approach to America's military role in the world.

Not surprisingly, he indicated he will pursue President Barack Obama's course of selective engagement, in contrast to the interventionism of the previous Republican administration, although he didn't specifically mention its war of choice in Iraq and other misadventurism.

"We can't dictate in the world," Mr. Hagel told Department of Defense employees, "but we must engage with the world." And, he added, "the resources that we employ on behalf of our country and our allies should always be applied wisely."

That view coincided with the first major challenge he faces, in the sharp budget cuts in military spending involved in Mr. Obama's tug-of-war with Republican congressional leaders over deficit reduction vs. higher taxes on the rich.

Before Mr. Hagel's nomination was confirmed by a 58-41 Senate vote, the narrowest endorsement of a secretary of defense on record, vocal critics in Congress and in the conservative blogosphere had predicted he would lose. Having erred in that wishful thinking, some have continued to warn he will be severely crippled as Pentagon chief.

If so, they will be able take some credit. They turned his confirmation hearing into a star-chamber proceeding on Mr. Hagel's past observations on the war in Iraq and pressures from the pro-Israel lobby. In the weeks thereafter, they continued a drumbeat aimed at creating a public impression that the Nebraskan was a gone goose. It reached the point where Sen. John McCain, leading the charge, flatly called Mr. Hagel unqualified to run the Pentagon, before finally acknowledging he would be confirmed.

Throughout that strong Republican effort to derail his nomination, Mr. Obama remained committed to get the man he wanted at Defense. In the end, his choice of a Republican didn't help him much with Senate Republicans, many of whom considered Mr. Hagel an unreliable cousin.

Mr. Obama got an independent thinker whose own decorated combat service in Vietnam made him sympathetic to the military, but not a knee-jerk advocate of all its budget demands.

Undoubtedly, as Mr. Hagel tackles the task of taming Pentagon spending, those critics disappointed at his confirmation will recall that he once talked about a "bloated" defense establishment. But within a reshaped second-term Obama administration, he seems a good fit with Obama and others determined to scale back  U.S. engagement abroad.

Mr. Hagel was an old ally of Vice President Joe Biden when he was chairman of the Senate Foreign Relations Committee. In the first Obama term, Mr. Biden had the president's ear on critical decisions involving the military. He counseled him to tread cautiously in urging more American troops into Afghanistan, and in monitoring their phased withdrawal from there and from Iraq.

Mr. Hagel joined Mr. Biden and then-Sen. John Kerry, now Mr. Obama's secretary of state, on committee fact-finding tours of Afghanistan, India, Turkey and Pakistan. In 2002, he joined Mr. Biden and Republican Sen. Richard Lugar in 2002 in a resolution that would have constrained President George W. Bush's invasion of Iraq as a last resort for disarming the country of its alleged weapons of mass destruction. Bush saw to it that the resolution went nowhere.

After the war started, Mr. Hagel joined Mr. Biden and Mr. Lugar in a trip to Iraq, and later cosponsored with them a resolution opposing Mr. Bush's plans to put in 20,000 more American troops to deal with disintegrating internal security. And he strongly urged Mr. Obama's decision to choose Mr. Biden as his running mate.

Whatever the Senate Republicans and other GOP critics think now of their old colleague taking charge at the Pentagon, he can count on strong administration backing in one of its most challenging tasks: maintaining a credible defense posture abroad while wrestling with shrinking resources at home.

At the same time, considering what often appears to be a paranoid determination of a disappointed Republican Party to make Mr. Obama's second term a failure, Chuck Hagel can expect to remain a prime target of his former colleagues. To many of them, he's now RINO -- a Republican In Name Only.

Jules Witcover is a former longtime writer for the Baltimore Sun. His latest book is "Joe Biden: A Life of Trial and Redemption" (William Morrow). You can respond to this column at juleswitcover@comcast.net.