Many candidates for the Republican presidential nomination have declared the horrific Paris terror attacks an assault on Western civilization, and some are now calling for more robust American action against ISIS — and taking aim at the Obama administration's policies in the Middle East.
Their reactions signal a new reality of the 2016 presidential campaign, putting the issues of national security and foreign policy front-and-center.
Even a temporary shift from the economic and social issues that have dominated the campaign so far could be pivotal for political outsiders like Donald Trump and Ben Carson, who lack traditional foreign policy experience, and for Rand Paul, who has been called an "isolationist" by his rivals.
The responses by GOP candidates covered some of the same common ground, with some advocating more direct involvement by the U.S.
Ohio Governor John Kasich said the NATO should consider invoking Article 5 of its charter, meaning the attacks would be considered attacks against all member nations and require the response of all, including the United States.
An "attack on one is an attack on all of us," Kasich told reporters after a speech in Florida.
On Saturday, Trump offered a moment of silence for the victims of the Paris attacks before targeting France's gun laws.
"If they had guns, if our people had guns … it would've been a much different situation," he said at a rally in Texas. He indicated he would stop the admission of refugees into the U.S. from the war-torn region.
While we "all have a heart," Trump said, to take in these refugees "is just insane."
Trump's position was echoed by rival Ted Cruz, who said in an interview with Fox News that the admission of "tens of thousands of Syrian Muslim refugees to America is nothing less than lunacy."
The Obama administration recently raised the number of Syrian refugees admitted to the U.S. from 2,000 to 10,000; all refugees must complete a security screening process before being allowed into the country.
To fight ISIS, Cruz wants to dramatically increase the number of U.S. airstrikes and arm Kurdish allies in the region. "In a Cruz administration, we would be using overwhelming airpower and the Kurds as our boots on the ground."
Former Arkansas Governor Mike Huckabee, meanwhile, is calling for the "immediate moratorium on admission to those persons from countries where there is strong presence of ISIS or Al-Qaeda."
Louisiana Governor Bobby Jindal, who on Saturday sent a letter to the White House demanding more information on Syrian refugees, said: "It's time for us here in America to secure our borders and to keep our people safe as well from these radical evil terrorists."
While Cruz and others are calling for increased airstrikes, neurosurgeon Dr. Ben Carson wants to go a step further, telling reporters in Florida: "Boots on the ground would probably be important."
He didn't get specific about how many troops that would include.
Neither did former Florida Governor Jeb Bush, who, when asked by radio host Hugh Hewitt if he would increase the number of boots on the ground, said: "I wouldn't put conditions on how many troops that's necessary to do that. I think you have to have a strategy, and then you can determine the number of people. We can't do it alone."
Sen. Lindsey Graham, in a TODAY interview, said that "every Arab government in the region would give us their armies. Turkey would also. But we'll have to be part of that force."
Bush called the fight against ISIS "the war of our time," saying "we have to be serious in engaging and creating a strategy to confront it and take it out." Marco Rubio also framed it as a "clash of civilizations" in a video released by his campaign on Saturday.
"You have to target [ISIS] safe havens." he said on Fox News. He added: 'I believe we need to subject ISIS to high-profile, humiliating defeats - meaning special operations attacks that are filmed, basically - so we can show the world these are not invincible people."
Rand Paul, who was called a "committed isolationist" by Rubio in the most recent Republican debate, did not directly answer questions on Saturday about how he would respond to the attacks if he were president.
Instead, he tied the attacks to the battle over the comprehensive immigration bill from 2013, legislation co-authored by Rubio, noting he offered an amendment to the bill that would have increased scrutiny on immigrants applying to the U.S.
Paul spoke to reporters at a gathering of Republican candidates in Orlando, Florida, where John Kasich also appeared and reiterated the need to enforce no-fly zones and work with allies to create safe havens for those displaced by war.
Noting that ISIS appears bent on destroying what he called the "Western ethic," he added the U.S. also needs to "win the war of ideas. Destroying one group does not allow us to win the battle of ideas."
Former Hewlett-Packard CEO Carly Fiorina said she would increase support to U.S. allies in the Middle East, including more weapons and better intelligence-sharing.
Fiorina was among the candidates — including Trump, Chris Christie, and others — who hit President Obama for his remarks a day before the Paris attacks that ISIS was "contained."
"From the start, our goal has been first to contain, and we have contained them," the president said on ABC News on Thursday. "They have not gained ground in Iraq. And in Syria, they'll come in, they'll leave. But you don't see this systematic march by ISIL across the terrain."
While national security has not been top-of-mind for voters for much of the 2016 race, it's a topic that takes on more importance to the Republican primary electorate than that of the Democrats.
According to the latest NBC News/Wall Street Journal poll, 11 percent of GOP primary voters said terrorism was their top concern; 12 percent said foreign policy and the Middle East topped the list. Both issues ranked in the single-digits for Democratic primary voters.
Iowa political scientist Steffen Schmidt, in a blog post, called the Paris attacks a "game changer for the Iowa caucuses and the 2016 US presidential elections," and Republican strategist Reed Galen tells NBC News it could "start to inject a serious dose of reality into the campaign."
But another GOP operative, noting previous overseas terror attacks in the run-up to the U.S. presidential elections, isn't so sure American voters will have such a visceral response: "These events don't have a massive effect this far out."