Barack Obama left the Senate after two years there for a presidential run, making few close friends in the chamber because of his short tenure. But before he left, Obama cultivated an unlikely bond with a Republican senator 29 years his senior: Richard G. Lugar.

In one of his first trips abroad as a senator, Obama joined Lugar’s annual voyage to Russia and Eastern Europe to inspect nuclear weapons facilities. Soon, Lugar was raving about how Obama always stayed until the end of the lengthy hearings the Indiana senator ran as head of the Senate Foreign Relations Committee. When Obama ran for president, Democrats floated Lugar’s name as a potential secretary of state.

But Libya has split the mentor from his pupil. After American forces joined NATO and Arab League nations in the conflict, Lugar emerged as one of the most vocal critics of the intervention.

Three months after he stood beaming behind Obama in the Oval Office as the president signed into law the new START agreement with Russia, Lugar has criticized Obama for deploying U.S. forces without a clear exit strategy, repeatedly called the conflict a “war” (a term the White House rejects), and all but said the president violated the Constitution in intervening without a formal authorization from Congress.

“The president still has not clearly stated what our goals are or what would constitute success. He has not stated whether the United States would accept a stalemate in the civil war, nor has he put forward a plan for ending Gaddafi’s rule,” Lugar said.

The senator’s criticisms of Obama’s Libya policy are similar to those of other members of both parties. But Lugar isn't just another lawmaker. He’s perhaps the most broadly respected Republican in Congress on foreign policy issues and a senior lawmaker who in 2007 told the Chicago Tribune that Obama has “a sense of idealism and principled leadership, a vision of the future.”

In a brief interview on Capitol Hill this week, the soft-spoken, 78-year-old senator played down his Libya criticism.

“My constituents are interested in jobs and the economy and I think they have appreciated the fact that I have spoken out on this issue, as I have on many others,” he said.

Tommy Vietor, a White House spokesman, would not discuss the apparent differences between the president and Lugar. But he said that “the president has enormous respect and affection for Senator Lugar, who has been a friend since the president’s early days in the Senate and whose opinion the President values greatly.”

Allies of Lugar said the lawmaker’s record is consistent — that he has long been wary of inserting U.S. forces without a clear strategy for victory and a guardian of Congress’ authority in foreign policy. In 1990, he worried that President George H.W. Bush was not informing Congress sufficiently about the war in Iraq, and more than a decade later tried to limit the authority of President George W. Bush to wage another war there, although Lugar in the end supported both decisions.

Courting conservatives?

Some in Indiana say Lugar is trying to woo conservatives in his home state, where he is facing a primary challenge from an opponent who has dubbed him “Barack Obama’s favorite Republican.”

But many in Washington argue that Lugar is a straight-shooter who has made little effort to court conservatives, even recently defending his votes for both of Obama’s Supreme Court nominees.

“Having known him for a long time, I think it’s a matter of principle,” said Lawrence Korb, a defense expert at the Center for American Progress, a liberal think tank. “I think he is very concerned about overextension of the U.S. military.”

Either way, the split has distanced Obama from perhaps his closest GOP ally on Capitol Hill.

During his 2008 presidential campaign, Obama aired an ad that featured his efforts in the Senate with Lugar to stop nuclear proliferation, even though Lugar had officially endorsed Sen. John McCain (R-Ariz.). The spot ran across the country, including in Indiana.

“How could we object?,” said Mark Helmke, a longtime Lugar adviser. “We made clear he was supporting McCain.”

But not on all issues. In an October 2008 speech, Lugar defended one of Obama’s most controversial stands in the campaign: that the U.S. president should directly negotiate with leaders of hostile regimes such as Iran. Later that day, at the last presidential debate, Obama named Lugar as one of the people “who have shaped my ideas and who will be surrounding me in the White House.”

During the past two years, Lugar was one of the few Republicans in Congress who was not consistently attacking Obama and his plans. In 2010, he called former Vice President Dick Cheney’s criticisms of Obama’s foreign policy stands “unfair.” Asked in an interview about his views on Obama’s foreign policy vision, he said, “I wouldn’t want to generalize.”

Accounts differ

But on Libya, Lugar is very specific: Obama is wrong. After a meeting in the Situation Room at the White House a few weeks ago among Obama and key lawmakers on Capitol Hill, Lugar left with the impression the president would not deploy U.S. planes, troops or ships into Libya.

Helmke said Obama told Lugar “Dick, there will be no boots on the ground or planes flying over Libya.” But White House officials dispute this account, saying that Obama only made assurances about ground troops.

The next day, as Libya government forces attacked rebels and threatened civilians, Obama authorized the use of American planes and ships to impose a no-fly zone and an arms embargo. Lugar immediately went on the attack, appearing repeatedly on television and hearings to argue against the president’s policy.

“On March 7, 12 days before the United States began hostilities, I called on the president to seek a declaration of war from the Congress if he decided to initiate hostilities. He declined to do that,” Lugar said at a hearing Thursday. “As a result, the United States entered the civil war in Libya with little official scrutiny or debate.”

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