President Bush used a speech to the Israeli Parliament on Thursday to liken those who would negotiate with “terrorists and radicals” to appeasers of the Nazis — a remark widely interpreted as a rebuke to Senator Barack Obama, who has advocated greater engagement with countries like Iran and Syria.

Mr. Bush did not mention Mr. Obama by name, and White House officials said he was not taking aim at the senator, though they were aware the speech might be interpreted that way.

The comments created an angry tussle back home, as Democrats accused Mr. Bush of breaching protocol by playing partisan politics overseas.

The episode placed Mr. Bush squarely in one of the most divisive debates of the campaign to succeed him, as Republicans try to portray Mr. Obama as weak in the fight against terrorism. It also underscored what the White House has said will be an aggressive effort by Mr. Bush to use his presidential platform to influence the presidential election.

“Some seem to believe that we should negotiate with the terrorists and radicals, as if some ingenious argument will persuade them they have been wrong all along,” Mr. Bush said, in a speech otherwise devoted to spotlighting Israel’s friendship with the United States.

“We have an obligation,” he continued, “to call this what it is: the false comfort of appeasement, which has been repeatedly discredited by history.”

Mr. Obama delivered a quick and pointed response, saying in an e-mail statement to reporters that he had no intention of dealing with terrorists and accusing Mr. Bush of using his visit, timed for the 60th anniversary of Israel’s independence, to “launch a false political attack.”

In an interview this week with a New York Times Op-Ed columnist, David Brooks, Mr. Obama addressed the criticism more directly. “I constantly reject this notion that any hint of strategies involving diplomacy are somehow soft or indicate surrender or means that you are not going to crack down on terrorism,” he said.

On Thursday, other Democrats leapt to the Illinois senator’s defense. Senator Harry Reid of Nevada, the Democratic leader, called Mr. Bush’s remarks “reckless and irresponsible.” Speaker Nancy Pelosi of California said Mr. Bush had behaved in a manner “beneath the dignity of the office of president.” Representative Rahm Emanuel of Illinois, chairman of the House Democratic caucus, accused Mr. Bush of violating the unwritten rule against playing politics overseas.

Senator Hillary Rodham Clinton, Mr. Obama’s rival for the Democratic presidential nomination, joined him in taking issue with Mr. Bush. Weighing in from South Dakota, Mrs. Clinton said: “President Bush’s comparison of any Democrat to Nazi appeasers is offensive and outrageous, especially in the light of his failures in foreign policy. This is the kind of statement that has no place in any presidential address.”

For Mr. Obama, the stakes are high. Many American Jews and Israelis view him with some suspicion, for several reasons. First, he has said he would be willing to meet with Mahmoud Ahmadinejad, the leader of Iran, who has called Israel “a stinking corpse” and denies its right to exist.

Second, an official of Hamas, the militant Palestinian group, has expressed hope for the Obama candidacy. (Mr. Obama has rejected that statement, and refers to Hamas as a terrorist group.) In addition, Mr. Obama’s advisers include Zbigniew Brzezinski, the former national security adviser, who some Jews believe has an anti-Israel tilt.

Mr. Obama has sought to counter the concerns with actions intended to telegraph his support for Israel, like appearing last week at the Israeli Embassy with a promise to “not only ensure Israel’s security but also to ensure that the people of Israel are able to thrive and prosper.”

In recent weeks, Senator John McCain, the presumptive Republican presidential nominee, has been playing on those worries by suggesting that Mr. Obama has received the “endorsement” of Hamas, a suggestion the Obama campaign hotly denies. On Thursday, Mr. McCain jumped into the fray over Mr. Bush’s remarks and wholeheartedly endorsed the president.

“Yes, there have been appeasers in the past, and the president is exactly right, and one of them is Neville Chamberlain,” Mr. McCain told reporters on his campaign bus after a speech in Columbus, Ohio.

Asked if he thought Mr. Obama was an appeaser, Mr. McCain sidestepped the question and said: “I think that Barack Obama needs to explain why he wants to sit down and talk with a man who is the head of a government that is a state sponsor of terrorism, that is responsible for the killing of brave young Americans, that wants to wipe Israel off the map, who denies the Holocaust. That’s what I think Senator Obama ought to explain to the American people.”

Thursday was not the first time the term “appeasement” has cropped up in the Bush administration lexicon. In 2006, in advance of the midterm elections, Vice President Dick Cheney and then-Defense Secretary Donald H. Rumsfeld invoked the analogy as a line of attack against critics of the war in Iraq. Then, as now, it was controversial.

Speaking with reporters here, Dana Perino, the White House press secretary, said that Mr. Bush’s comment was not a reference to Mr. Obama and that the president was simply repeating his longstanding views.

“I understand when you’re running for office you sometimes think the world revolves around you — that is not always true and it is not true in this case,” Ms. Perino told reporters here.

While campaigning for Congressional Republicans in 2006, Mr. Bush did similarly imply that Democrats believed they could “negotiate with these folks,” that is, terrorists.

Mr. Obama’s foreign policy aides said any high-level talks with Iran would have the primary intention of persuading it to end its support for terrorist groups like Hezbollah and Hamas, to end its aggressive stance against Israel and to cease its uranium enrichment program. Unlike Mr. Bush, however, Mr. Obama would not make the end of that program a precondition for talks.

(Speaking on Fox News Channel, an Obama foreign policy adviser, Susan E. Rice, said his openness to meeting with Iranian leadership was not necessarily restricted to Mr. Ahmadinejad.)

As for Hamas, Mr. Obama’s aides said his position on engagement was not different from that of the administration; the group would have to renounce terrorism, recognize Israel and agree to abide by all pre-existing Palestinian treaties with Israel.

And as Mr. McCain and Mr. Bush drew historic parallels to Chamberlain, Mr. Obama and his aides drew some of their own — to President Richard M. Nixon’s cold-war reaching out to China and President Ronald Reagan’s reaching out to the Soviet Union.

Mr. Obama has likened his foreign policy approach to that of the so-called pragmatists in the administration of the first President George Bush, which carried out the first American invasion of Iraq, in 1991, and he has shared those sentiments recently as he has sought to woo independent voters in swing states.

“I have enormous sympathy for the foreign policy of George H. W. Bush,” he said. “I don’t have a lot of complaints about their handling of Desert Storm. I don’t have a lot of complaints with their handling of the fall of the Berlin Wall.”