DES MOINES, Iowa — Barack Obama had the distinction Sunday of being the most-talked-about Democratic presidential candidate during the debate by candidates seeking the Republican nomination for the presidency.

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The Illinois senator was singled out for his comments last week about foreign policy matters.

Former Massachusetts Gov. Mitt Romney, who leads the GOP candidate field in Iowa, said, "In one week, he went from saying he's going to sit down, you know, for tea, with our enemies, but then he's going to bomb our allies. I mean, he's gone from Jane Fonda to Dr. Strangelove in one week."

Obama said last week that the United States should focus its anti-terrorism efforts on Pakistan and Afghanistan, using force and additional troops there, if necessary.

His plan for dealing with global terrorism calls for withdrawing U.S. troops from Iraq and shifting more of the anti-terrorism effort to Pakistan and Afghanistan. He also called for sending two more brigades to Afghanistan, roughly 7,000 soldiers, as well as developing stronger partnerships with European nations and with NATO, the organization of U.S. allies.

Obama said he would not send troops to Pakistan unless doing so was a last resort to capture terrorists such as Osama bin Laden and if Pakistan's leaders failed to cooperate with the United States.

Later in the week, when asked about terrorist targets in Afghanistan and Pakistan, Obama said, "I think it would be a profound mistake for us to use nuclear weapons in any circumstance." He then added: "Involving civilians." He paused, then said, "Let me scratch that. There's been no discussion of nuclear weapons. That's not on the table."

During Sunday's Republican debate in Des Moines, former New York City Mayor Rudy Giuliani said Obama did not express it the right way. Giuliani said he would not take the nuclear option off the table.

U.S. Rep. Duncan Hunter of California said Obama "didn't understand" the situation. Romney also said that he believes Obama "is confused as to who are our friends and who are our enemies."