WASHINGTON — The Senate’s only “independent Democrat” is lashing out at the party whose vice presidential nominee he once was, accusing its leaders of betraying the tradition of presidents Roosevelt, Truman, and Kennedy.

At a speech before Johns Hopkins University’s School of Advanced International Studies, Senator Lieberman of Connecticut said, “Since retaking Congress in November 2006, the top foreign policy priority of the Democratic Party has not been to expand the size of our military for the war on terror or to strengthen our democracy promotion efforts in the Middle East or to prevail in Afghanistan. It has been to pull our troops out of Iraq, to abandon the democratically elected government there, and to hand a defeat to President Bush.”

Those words were part of a speech that traced Mr. Lieberman’s own position on the war in the tradition of not only the great Democratic presidents of the 20th century, but also the interventionism of President Clinton and his vice president, Albert Gore, a man who has played to the net roots base that tried and failed to unseat Mr. Lieberman in 2006.

Mr. Lieberman was particularly critical of his 22 Democratic colleagues in the Senate who voted against the senator’s resolution to label Iran’s revolutionary guard corps and elite Quds Force a foreign terrorist entity. He accused liberal Web logs of peddling a “conspiracy theory,” namely that the legislation was a back door authorization for war. Also, without naming names, he said some of his colleagues who had voted against it said they agreed with its substance, but told the senator, “We don’t trust Bush. He’ll use this resolution as an excuse for war against Iran.”

Mr. Lieberman concluded, “There is something profoundly wrong-something that should trouble all of us — when we have elected Democratic officials who seem more worried about how the Bush administration might respond to Iran’s murder of our troops, than about the fact that Iran is murdering our troops.” He added, “There is likewise something profoundly wrong when we see candidates who are willing to pander to this politically paranoid, hyper-partisan sentiment in the Democratic base — even if it sends a message of weakness and division to the Iranian regime.”

A senior aide to Mr. Lieberman said the senator was attempting to draw out the long arc of the modern Democratic Party’s approach to foreign affairs and persuade fellow Democrats that now was the time to embrace the Truman-Kennedy tradition again.

“We wanted to put our positions in the context of a national tradition,” he said. “Maybe some Democrats will be open to listening to this. It was an appeal for the Democratic Party to return to its tradition.”

A spokesman for the Senate majority leader, Harry Reid, a Democrat from Nevada said, “Senator Reid and Senator Lieberman agree on many issues, but when it comes to the war in Iraq they have a deep and significant difference of opinion. Senator Reid, along with a majority of the American people, supports the idea that we need to start bringing our troops home. That is what he believes in, and that is what he is going to continue to fight for.”

Recently however, other Democratic leaders have credited the military surge they sought to stop earlier this year with the decrease in violence in Iraq. On Tuesday, the House majority leader, Steny Hoyer, a Democrat of Maryland, told the Cybercast News Service that he credits the surge with the military success. The Christian Science Monitor, however, quoted Mr. Hoyer as saying he still believed the Iraq war was “perhaps the most seriously flawed implementation of a foreign policy in my lifetime and maybe in our history.”

A former foreign policy adviser to Vice President Gore, Andrei Cherny, said he is predicting Democrats to tack to the center as soon as the presidential nomination process wraps up.

“There is a large grain of truth that Lieberman is very much overstating,” said Mr. Cherny, who is also editor of Democracy: A Journal of Ideas. “He is absolutely right that so far we have not heard in the presidential primaries, candidates speaking to the Democratic tradition of expanding democracy around the world and using force to advance American values, and that is in large part because of the sense that America is in a dire situation in Iraq. I think we will see the Democratic nominee return to these kinds of values.”

Mr. Cherny just finished writing a book exploring President Truman’s political campaign against his first secretary of commerce, Henry Wallace. Mr. Wallace campaigned for the presidency in 1948 on a platform that called for a soft line on Stalin’s Soviet Union.

Mr. Cherny said he did not think the Democrats were in danger of embracing the kind of appeasement associated with Wallace or later the party’s 1972 nominee, George McGovern.

“I don’t think we are on the cliff of Henry Wallace. It is a party that is at sea, it is a party that is not in the same way advancing its historic mission. We have not wandered into the wooly headed appeasement of Henry Wallace,” Mr. Cherny said. “That being said, we do need a strong figure to return us to the kind of approach that Harry Truman represented.”