Sen. Marco Rubio is positioning himself as the leading foreign policy hawk among Republicans considering runs for the White House, pushing for more military spending and greater intervention abroad as the United States confronts Islamic State extremists in Iraq and Syria.

The Florida senator and potential Republican presidential candidate supports President Barack Obama’s strategy to arm moderate Syrian rebels battling the militants — and says American combat troops may be necessary to stop the march of Islamic State forces across the Middle East. On Wednesday, he is set to deliver a major national security speech at a conservative gathering in Washington, in which he is expected to call for increased defense spending and a reinvigorated American military.

Those positions create a contrast with some of his potential GOP rivals and could help repair Rubio’s relations with conservative activists upset over his support for an immigration overhaul last year. The tough talk about fighting Islamic State extremists also could quell concerns among a broader swath of Republicans about the 43-year-old freshman senator’s inexperience in global affairs — seen as a key vulnerability if Democrats nominate former Secretary of State Hillary Rodham Clinton in 2016.

Republican leaders see Obama’s focus on winding down wars in Iraq and Afghanistan and a reluctance to use force as ripe for GOP critique in the coming presidential campaign. But some worry that their party’s crop of young lawmakers would make less-than-convincing messengers.

Rubio’s focus on foreign policy “allows someone who was the speaker of the House in Florida to preface his answers with, ‘I said to the king of Jordan’ and ‘The prime minister of Japan said to me,’” said Elliott Abrams of the Council on Foreign Relations. “That kind of statement is important when you’re trying to prove, ‘I know what I’m talking about.’”

There also is significant political risk. Recent polls show strong public support for military action in Iraq and Syria. But public opinion can swiftly change after a decade of conflict in Iraq and Afghanistan. Experts forecast a prolonged campaign against a terrorist group that spans several countries.

“Most Americans are not only war-weary but very wary of being left with a hostile situation and really no civil government that’s there on the ground,” said Richard Lugar, the former Republican senator from Indiana who led the Foreign Relations Committee.

In recent months, Rubio has used his perch as one of only two Republicans senators on the Foreign Relations and Intelligence committees to push for robust engagement on the world stage. He advocated tougher sanctions against Russia after its annexation of Crimea and its incursion into Ukraine and now wants the U.S. government to crack down on Venezuelan officials for human rights violations.

In an opinion piece aimed as much at his potential GOP rivals as Obama, Rubio took to the pages of The Washington Post last week to criticize the president for what he characterized as “the most disengaged presidential foreign policy in modern American history.” He argued that the administration’s failure to arm the Syrian rebels years ago — a plan he has long advocated — had helped foster the rise of “perhaps the most extreme, powerful and capable terrorist group ever.”

“Presidents are not supposed to be witnesses to history,” he wrote. “They are supposed to help shape it in America’s favor.”

Obama resisted military engagement in Syria for more than three years, wary of dragging the U.S. into yet another seemingly intractable Mideast conflict. He avoided arming rebels who oppose President Bashar Assad out of concern those weapons could fall into extremist hands. With the public opposed to intervention at the time, even Rubio opposed giving Obama authority to use missile strikes last year, saying the administration had waited too long to intervene.

The growing threat from Islamic State militants and the beheadings of two American journalists have changed those calculations.

For now, with recent polls showing majorities of Americans in both major political parties supporting plans for a military campaign against Islamic militants in Iraq and Syria, some GOP critics have begun to echo Rubio and other hawks in the party.

Earlier this month, Sen. Rand Paul, R-Ky., who had been skeptical of U.S. airstrikes, argued for some military force against the extremists in an opinion piece in Time magazine under the headline, “I Am Not an Isolationist.” And Sen. Ted Cruz of Texas, another possible presidential contender who had been reluctant about American intervention, recently told activists at a conservative conference, “We ought to bomb (the militants) back to the Stone Age.”

Unlike Rubio, however, Paul and Cruz oppose arming Syrian rebels, citing concerns about the ability to identify moderates in a country awash with rebel formations and shifting alliances.

(AP)