DeSantis said the U.S. Navy isn't large enough and he'd expand it significantly to meet China's threats. Right now, the U.S. Navy has 291 ships but DeSantis says his plan would be 385 ships by the end of two terms.

The Florida governor compared the threat of China today to the threat of the Soviet Union post-World War II, warning a Chinese superpower would want to "export authoritarianism" around the world.

"I think the future of freedom is going to be determined in the Indo-Pacific," he said. "We have a strategy not just with military but decoupling from the economy and fighting them here at home."

He then went after Haley for recruiting Chinese companies to invest in South Carolina when she served as governor, while he's worked to ban Chinese citizens from buying land in Florida.

-ABC News' Alexandra Hutzler

Americans once had fairly mixed views of China, but they have become far more negative in the past five or so years, based on data from the Pew Research Center. In 2018, 47% of Americans had an unfavorable view of China while 38% had a favorable one. But that unfavorable percentage shot up to 60% in 2019 and it's only risen further since -- a whopping 82% said they had an unfavorable view in 2022. The national security and foreign policy attacks that Republican candidates have made on China in this debate likely resonated, although Americans tend not to list overseas concerns as a top worry.

-Analysis by Geoffrey Skelley of 538

Scott, Haley and Christie sounded support for Ukraine against Russia while Ramaswamy and DeSantis were more skeptical of how much Washington should back Kyiv.

"We have been very effective using our resources and our weaponry and the very high price of Ukrainian blood to achieving that objective," Scott said of degrading Russia's military.

Still, Scott argued, "The American people are frustrated that they do not have a president who reminds us and tells us where's the accountability -- how are those dollars being spent? We need those answers for us to continue to see the support for Ukraine."

Haley said she does not support handing Ukraine cash but that the U.S. should "give them the equipment and the ammunition to win."

Christie, meanwhile, argued support for Ukraine "is the price we pay for being leaders of the free world."

Ramaswamy, who has hammered Ukraine throughout his campaign, called Ukraine corrupt.

"To frame this as some kind of battle between good and evil, don't buy it," he said.

DeSantis, meanwhile, sought to pivot to immigration but said, "We are not going to send your sons and daughters to Ukraine."

-ABC News' Tal Axelrod

Ramaswamy is different from his colleagues when it comes to Ukraine, generally arguing that the United States pull away from Ukraine’s fight against Russian invaders.

“Ukraine is not a paragon of democracy,” Ramaswamy said. “This is a country that has banned 11 opposition parties.”

His point about political parties is accurate, but it needs context.

Ukraine banned 11 pro-Russian parties -- the largest of which occupied 44 out of 450 seats in Ukraine's Parliament, according to Radio Free Europe. The party’s leader, Viktor Medvedchuk, is aligned with Russian President Vladimir Putin. Putin is the godfather of Medvedchuk's daughter, Radio Free Europe reported.

-Analysis by Aaron Sharockman of PolitiFact

“Three out of four Americans agree with a 15-week limit,” Scott said.

Survey data varies on this question. A June 2023 poll sponsored by Susan B. Anthony Pro-Life America, an anti-abortion group, and conducted by the Tarrance Group, found that 77% of respondents said abortions should be prohibited at conception, after six weeks or after 15 weeks.

But this poll was sponsored by a group with a position on the issue, and both questions told respondents that fetuses can feel pain at 15 weeks -- an assertion that is not the universal consensus among medical experts.

Independent polls found a range of results on the question of an abortion ban after 15 weeks. A July 2022 survey from Harvard University’s Center for American Political Studies and the Harris Poll found that 23% of respondents said their state should ban abortion after 15 weeks, 12% said it should be banned at six weeks and 37% said it should be allowed only in cases of rape and incest. Collectively, that’s 72% who supported a ban at 15 weeks or less.

In two subsequent polls, the support for abortion at 15 weeks or less was not as strong. A September 2022 Economist/YouGov poll found that 39% of respondents supported a ban on abortions after 15 weeks, and 46% opposed it. And a June 2023 Associated Press-NORC poll found that for abortion up to 15 weeks, 51% of respondents said they would allow it, while 45% said they would ban it.

-Analysis by Aaron Sharockman of PolitiFact