The top Republican presidential candidates will face off on Wednesday during the third Republican primary debate, hosted by CNBC at the University of Colorado Boulder. The main event is slated to begin at 8 p.m. Eastern.
The debate will focus on key economic issues like jobs, taxes and healthcare, but it is also expected to stray into other, more controversial topics like immigration and their strategies for combatting the terrorist group Islamic State in Iraq and Syria, also known as ISIS.
Here's where the top Republican candidates stand on ISIS.
Business tycoon Donald Trump: Trump is confident in his ability to defeat ISIS through hostile military strategy. In August, Trump said he wants U.S. troops fighting ISIS on the ground in the Middle East — and that he's going to take their oil for the United States.
"I would knock out the source of their wealth, the primary sources of their wealth, which is oil," he said on MSNBC's Morning Joe. "And in order to do that, you would have to put boots on the ground. I would knock the hell out of them, but I'd put a ring around it and I'd take the oil for our country. I'd just take the oil."
On Monday's episode of NBC's Today, Trump said he approves of Russia bombing ISIS in Syria, as long as the U.S. does it too. "If Russia wants to go into Syria and bomb the hell out of ISIS, I'm sort of okay with that," Trump told Today, the Huffington Post reports. "But we have to do it too."
The problem with Trump's statement is that Russia is actually bombing Syrian rebels and civilians who oppose the regime of President Bashar al-Assad. Additionally, the U.S. and its allies have already been bombing ISIS for over a year. The U.S. spends $10 million each day launching aircrafts from the Middle East, according to Sunday's episode of 60 Minutes, which disclosed that there are more than 160 aircrafts over Iraq and Syria every day.
Huffington Post reports Trump also said onToday that he "would build our military so strong and so good ... that no one is going to mess with us."
Retired neurosurgeon Ben Carson: Carson has a theme of building his political theories on the Bible, and his stance on ISIS is no exception. In a March interview with conservative radio host Hugh Hewitt, Carson compared the story of radical Islam to the Biblical story of Jacob and Esau.
"Well, first of all you have to recognize they go back thousands and thousands of years, really back to the battle between Jacob and Esau," he said in the interview. "But it has been a land issue for a very long period of time."
In February, Carson told Fox News that the war against ISIS can't have rules, because "war" and "rules" contradict each other.
"Our military needs to know that they're not going be prosecuted when they come back, because somebody has said, 'You did something that was politically incorrect,'" Carson told Fox News. "There is no such thing as a politically correct war. We need to grow up; we need to mature. If you're gonna have rules for war, you should just have a rule that says no war. Other than that, we have to win. Our life depends on it."
Texas Sen. Ted Cruz: Cruz has an apocalyptic view of the terrorist group. In a post written for CNN in September, Cruz insisted that the U.S. must protect its border from a possible domestic ISIS attack.
"First and foremost," he wrote in the blog post, "Washington should resolve to make border security a top priority finally, rather than an afterthought, of this plan in light of concerns about potential ISIS activities on our southern border," citing a Texas Department of Public Safety bulletin from a Fox News report.
Cruz also asserted that any American who "supports" or "fights for" ISIS should have their citizenship revoked. "Congress should make fighting for or supporting ISIS an affirmative renunciation of American citizenship," he wrote in the CNN post. "Numerous Americans have joined ISIS along with hundreds of others from the European Union."
Finally, Cruz stressed that the U.S. must focus on military action to defeat ISIS. "Because of the very nature of ISIS," he wrote in the CNN post, "the response must be principally military," adding that "we should concentrate on a coordinated and overwhelming air campaign to destroy the capability of ISIS to carry out terrorist attacks on the United States."
Florida Sen. Marco Rubio: In February, at the Political Conservative Action Conference, Rubio said he would build a military coalition led by Sunni countries in the region to fight ISIS on the ground, supported by U.S. air power.
"Put together a coalition of armed regional governments to confront [ISIS] on the ground with U.S. special forces support, logistical support, intelligence support and the most devastating air support possible," he said at the conference, the Huffington Post reported, "and you will wipe ISIS out."
In the same speech, Rubio criticized President Barack Obama for his so-called lack of military policy against ISIS. "The reason Obama hasn't put in place a military strategy to defeat ISIS is because he doesn't want to upset Iran," he said, according to the Huffington Post.
MSNBC's Steve Benen pointed out two issues with Rubio's critique on the MaddowBlog: ISIS and Iran are enemies, and Rubio's plan is quite similar to that of Obama.
"Tehran is more than happy to see U.S. forces go after ISIS targets," Benen wrote in the post of Iran's stance on ISIS. "In fact, Iran has done the same thing. When it comes to the terrorist group, Americans and Iranians are on the same side. How could Rubio not know this?"
"The argument that Obama 'hasn't put in place a military strategy to defeat ISIS' is plainly untrue," Benen wrote on the MaddowBlog. "Rubio should know this, not only because he's a member of the Senate Foreign Relations Committee and an unannounced presidential candidate, but also because Obama's strategy to defeat ISIS is largely identical to Marco Rubio's."
Florida Gov. Jeb Bush: In a foreign policy speech at the Ronald Reagan Presidential Library in August, Bush detailed a strategy against ISIS that involves a no-fly zone over Syria and U.S. troops on the ground in the Middle East, CNN reports, criticizing Obama and former Secretary of State and Democratic presidential front-runner Hillary Clinton for pulling U.S. troops out of Iraq.
"So eager to be the history-makers, they failed to be the peacemakers," Bush said during the address, CNN reports. "Rushing away from danger can be every bit as unwise as rushing into danger, and the costs have been grievous."
He then affirmed his dedication to rebuilding military force against ISIS if elected. "I assure you: The day that I become president will be the day that we turn this around and begin rebuilding the armed forces of the United States," he said, CNN reports.
Bush also asserted that a no-fly zone over Syria is pertinent to fight ISIS and protect the Syrian people from President Bashar al-Assad's regime.
Former Hewlett-Packard CEO Carly Fiorina: At an October campaign rally in New Hampshire, Fiorina said she'll apply her Stanford University bachelor's degree in medieval history and philosophy to defeat ISIS.
"Finally my degree in medieval history and philosophy has come in handy," Fiorina said at the rally, ABC reports, "because what ISIS wants to do is drive us back to the Middle Ages, literally." She rattled off several techniques ISIS uses that relate to that of the medieval times. "Every single one of the techniques that ISIS is using — the crucifixion, the beheadings, the burning alive — those were commonly used techniques in the Middle Ages," Fiorina told reporters at the event, according to ABC.
However, Fiorina doesn't believe in embedding U.S. troops on the ground in the Middle East. Instead, she said on ABC News's This Week With George Stephanopoulos in August the U.S. should be providing those fighting ISIS in the Middle East with the tools they've been "requesting" for years. "We really are sitting by when we could be leading a coalition of Arab allies to defeat ISIS," she said, the Hill reported. "I think the Jordanians, the Saudis, the Kuwaitis, the Kurds and the Egyptians are all fighting ISIS as we speak on the ground."
"They know this is their fight," she said, according to the Hill. "Yes, they need leadership, resolve support and material from us. We haven't provided any of it. And if we did, it will make a big difference."