WASHINGTON — A roiling national debate over how to deal with the radical Islamic State and other global hot spots has prompted a sudden shift in Republican politics, putting a halt to the anti-interventionist mood that had been gaining credence.

The change is evident on the campaign trail ahead of the November midterm elections and in recent appearances by prospective 2016 Republican presidential candidates, with a near-universal embrace of stronger military actions against the group that has beheaded two American journalists.

A hawkish tone has become integral to several key Republican Senate campaigns, with a group of candidates running in battleground states calling attention to their ties to veterans and their support for the U.S. military at every turn.

In contests in Iowa, Arkansas and Alaska – where Republicans are running for seats held by Democrats – the Republican candidates are military veterans and focusing much of their time extolling their expertise.

A thirst among many conservative activists for a more muscular U.S. foreign policy was clear over the weekend at a meeting of Americans for Prosperity, the tea-party-affiliated group backed by the billionaire Koch brothers. The loudest applause came when Sen. Ted Cruz, R-Texas, a potential presidential candidate, called for bombing the Islamic State “back to the Stone Age.”

Even Sen. Rand Paul, R-Ky., a leader of the anti-interventionist Republican wing who is seen as a top-tier contender for the 2016 presidential nomination, has joined in the calls for a more hawkish approach.

The party’s changing tenor on foreign policy underscores the extent to which the party continues to struggle to forge its identity in the wake of the George W. Bush presidency.

Libertarian-leaning conservatives gained momentum in part by criticizing the Iraq War and the growth of government on Bush’s watch.

Their heightened clout led to clashes with prominent Republican hawks such as Sen. John McCain of Arizona and New Jersey Gov. Chris Christie, who openly challenged Paul’s worldview as weak and dangerous.

The tensions came to a head last year, when a measure to curtail the NSA’s data collection was only narrowly defeated in the Republican-led House and served as a warning to Republican officials that the Paul wing was ascendant in Congress and willing to challenge the party’s long-held positions on foreign policy and national security.

But now, with a series of competitive Senate races poised to determine control of the chamber and the Republican Party facing a wide-open contest for its presidential nomination, growing public unease with the U.S. role in the world is prompting many Republicans to revert to a more familiar, anti-isolationist stance.

Not only are Republicans calling broadly for aggressive actions against the Islamic State, they are also accusing President Obama of failing to stand up to Russian President Vladimir Putin and not doing enough to stand by Israel amid its recent fighting with Hamas.

According to a Pew Research Center poll released last week, 46 percent of Republicans said the United States does “too little” to help solve global problems – a 28-point increase from the previous poll, last November. The percentage of Republicans who believe the U.S. does “too much” abroad has dropped from 52 percent to 37 percent.

“Things are moving back in that hawkish direction, reflecting the mood of most Americans who are angry at what they’re seeing,” said Brian Walsh, a former adviser to the National Republican Senatorial Committee.

William Kristol, editor of the Weekly Standard and a leading pro-interventionist voice on the right, said Republicans are moving back to their “inner hawkishness.” He said that some in the party had been “a little intimidated for a while … by the so-called libertarian moment” but that Republican candidates are now showing a greater willingness to extend their foreign policy statements beyond mere attacks on Obama.

“What heartens me is that candidates are … talking about the need for a different approach, about how we can’t freak out when someone mentions potentially putting boots on the ground,” Kristol said.

Recent moves by Paul illustrate how some top Republicans are still searching for the party’s foreign policy sweet spot.

Two months ago, the Kentucky senator, who had been a vocal critic of the war in Iraq, wrote a Wall Street Journal op-ed chiding advocates for expanding the U.S. troop presence and deploying airstrikes.

But with the Islamic State taking center stage, Paul has started to sound more sympathetic to an interventionist policy.

“If I were president, I would call a joint session of Congress. I would lay out the reasoning of why ISIS is a threat to our national security and seek congressional authorization to destroy ISIS militarily,” he said in a statement from his office.

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