FACTBOX: Should a U.S. president talk with foreign adversaries?

(Reuters) - President George W. Bush suggested on Thursday that calls for direct talks with the leader of Iran or with "radicals and terrorists" amounted to "the false comfort of appeasement."

His comments was seen as a swipe at Democratic presidential contender Barack Obama, who has said he favors talking with the leaders of countries hostile to Washington.

Following are comments by some prominent U.S. political figures on engaging U.S. adversaries:

PRESIDENT GEORGE W. BUSH, speaking to the Israeli parliament on Thursday:

"Some seem to believe we should negotiate with terrorists and radicals, as if some ingenious argument will persuade them they have been wrong all along. We have heard this foolish delusion before. As Nazi tanks crossed into Poland in 1939, an American senator declared: 'Lord, if only I could have talked to Hitler, all of this might have been avoided.' We have an obligation to call this what it is -- the false comfort of appeasement, which has been repeatedly discredited by history."

DEMOCRAT PRESIDENTIAL CANDIDATE BARACK OBAMA, asked in a July 23, 2007, candidates' debate whether he would be willing to meet without precondition with the leaders of Iran, Syria, Venezuela, Cuba and North Korea during his first year in office:

"I would. And the reason is this, that the notion that somehow not talking to countries is punishment to them -- which has been the guiding diplomatic principle of this administration -- is ridiculous."

PRESUMPTIVE REPUBLICAN PRESIDENTIAL CANDIDATE JOHN MCCAIN, talking to reporters on Thursday, criticized Obama's stand, especially talking with the Iranian leader:

"It is a serious error on the part of Senator Obama. It shows naivete and inexperience and lack of judgment to say that he wants to sit down across the table from an individual who leads a country that says that Israel is a stinking corpse, that is dedicated to the extinction of the state of Israel. My question is, what does he want to talk about?"

U.S. DEFENSE SECRETARY ROBERT GATES, in a May 14, 2008, speech to the American Academy of Diplomacy:

"We need to figure out a way to develop some leverage with respect to the Iranians and then sit down and talk with them. If there's going to be a discussion, then they need something, too. We can't go to a discussion and be completely the demander with them not feeling that they need anything from us."

FORMER PRESIDENT AND NOBEL LAUREATE JIMMY CARTER, speaking to ABC News before his April 17, 2008 meeting with Hamas leaders in Egypt:

"I think there's no doubt in anyone's mind that, if Israel is ever going to find peace with justice concerning the relationship with their next-door neighbors, the Palestinians, that Hamas will have to be included in the process.

"I think someone should be meeting with Hamas to see what we can do to encourage them to be cooperative."

FORMER SECRETARY OF STATE JAMES BAKER, CO-CHAIRMAN OF THE IRAQ STUDY GROUP, speaking before the Senate on December 7, 2006, in defense of the panel's recommendation that Washington engage Iran and Syria for help in stabilizing Iraq:

"What do we lose by saying, 'We're getting all of Iraq's neighbors together, we want you to come,' and if they say no, we show the world what they're all about?"