(Richard Shiro/AP Photo)

SPARTANBURG, S.C. – In the midst of a campaign that thus far has focused primarily on domestic issues such as this country’s struggling economy, the Republican presidential candidates tonight turned their attention abroad at a foreign policy debate here in this crucial primary state, the first in the South.

With no epic gaffes such as Rick Perry’s “oops” moment earlier this week in Detroit or heated exchanges like Mitt Romney’s argument with Perry last month in Las Vegas, the debate at Wofford College was a more muted, policy-driven affair. While anyone looking for fireworks would have left disappointed, wonks would have felt otherwise.

Instead of taking shots at one another, the candidates directed their most stinging attacks at President Obama, with Romney going so far as to say that if voters do not want Iran to have a nuclear bomb, they should support him, but if they do want Iran to develop a nuclear arsenal, then they should back the president.

Earlier this week the International Atomic Energy Agency released a report stating that they have “serious concerns regarding possible military dimensions to Iran’s nuclear programme,” their most unequivocal statement yet that Iran is attempting to produce atomic weaponry.

Newt Gingrich, who has surged in the polls in the past month, called for covert operations in Iran, even assassinating Iranian scientists who are working on their nuclear arsenal. Such actions, he noted, would be done “all covertly, all deniable.”

Herman Cain, for his part, said he would first “assist the opposition movement” in Iran in their push for regime change.

“Our enemies are not the people of Iran, it’s the regime and a regime change is what they are trying to achieve,” Cain said. “Secondly, we need to put economic pressure on Iran by way of our own energy independence strategy. By having our own energy independence strategy we will impact the price of oil on the world market because Iran uses oil, not only as a means of currency but they use it as a weapon.”

Romney, Gingrich, and Cain occupy the top three spots in the latest GOP polls. A CBS News poll of likely Republican primary voters, released Friday, showed Cain in the lead with 18 percent support, ahead of Romney and Gingrich, both tied at 15 percent. Another poll, conducted by Marist/McClatchy of Republicans and GOP-leaning independents, revealed Romney in first place with 23 percent support, followed by Gingrich at 19 percent and Cain at 17 percent.

While Gingrich has surged and Romney has held steady, Cain continues to combat the sexual harassment allegations that were leveled at him in the past two weeks. A Gallup poll released this week found a recent decline in the businessman’s personal favorability rating. Cain’s Positive Intensity Score was 29 in interviews conducted the week before the harassment allegations came out, but fell to 20 the following week. Additional polling suggests that Cain’s trajectory has flattened lately. In a Quinnipiac poll of Florida this week, the former Godfather’s Pizza CEO had 27 percent support, down from 32 percent support in an NBC/Marist poll there in the middle of October.

Other than former Ambassador Jon Huntsman, none of the GOP candidates can boast of a great deal of foreign policy experience. Some, such as Cain, at times appeared more uncomfortable on national security issues than they usually do when discussing domestic matters, while the more experienced ones — including Huntsman and Rep. Michele Bachmann who sits on the House Intelligence Committee – were relegated to bit parts. Instead the bulk of the debate was dominated by Romney and Perry, the two candidates with the largest war chests, a disparity that provoked the ire of Bachmann, Huntsman, and Rep. Ron Paul.

Perry, looking to bounce back after a disastrous debate performance on Wednesday in Michigan, produced a stronger showing in South Carolina. The Texas governor embarked on a media blitz the day after Wednesday’s debate, made an ad buy worth nearly $1 million on FOX News, and looked assured in front of the Wofford College audience. Perry even managed to joke about his infamous gaffe when he forgot the third federal agency that he wanted to eliminate.

“You advocate the elimination of the Department of Energy…,” said CBS News’ moderator Scott Pelley.

“Glad you remembered it,” quipped Perry.

“I’ve had some time to think about it, sir,” joked Pelley.

“Me too,” Perry replied.

The most heated moment of the debate came when Perry took exception with Paul’s response to a question about torture.

“This is war,” Perry stated. “That’s what happens in war, and I am for using the techniques, not torture, but using those techniques that we know will extract the information to save young Americans lives and I will be for it until I die.”

After two debates in the span of the past of four nights, the candidates will now get a brief respite from one another: the next debate, also set to focus on foreign policy, will take place the week of Thanksgiving in Washington, D.C.

South Carolina will be the third state to vote in the GOP primary this winter, with its primary set for Jan. 21. The Iowa caucuses kick off the cycle at the beginning of January.

Matthew Jaffe is covering the 2012 campaign for ABC News and Univision.