Waterloo Courier, Matthew Putney, Associated Press
U.S. Sen. Rand Paul, R-Ky., speaks at a campaign event for Republican businessman Rod Blum, who is running against Democratic state lawmaker Pat Murphy in the 1st Congressional District, Wednesday, Oct. 22, 2014, on the University of Northern Iowa campus in Cedar Falls, Iowa.

NEW YORK — Sen. Rand Paul is taking on critics who brand him an isolationist on foreign policy, advocating an approach for America that "recognizes our limits and preserves our might."

The libertarian-leaning Republican, a possible White House contender in 2016, is setting out the limits he sees for U.S. involvement in military conflicts.

"America shouldn't fight wars where the best outcome is stalemate. America shouldn't fight wars when there is no plan for victory," he says in a speech scheduled for Thursday night at the Center for the National Interest. "America should and will fight wars when the consequences — intended and unintended — are worth the sacrifice."

"A precondition to the use of force must be a clear end goal. We can't have perpetual war," according to his prepared remarks, obtained by The Associated Press.

Paul has drawn sharp criticism from within his own party for favoring a smaller American footprint on the international stage. The first-term Kentucky senator has called for the end of all foreign aid and the closure of U.S. military bases abroad.

Similar positions helped sink the presidential ambitions of his father, former Texas Rep. Ron Paul. That's a fate the younger Paul is working hard to avoid. Polling suggests that a war-weary American public might respond well to Paul's reframing, even if his positions concern some of the Republican Party's most powerful donors and opinion leaders.

Over the past year, the senator has courted foreign policy leaders across the political spectrum. In Thursday's speech, he was trying to distance himself further from the isolationist label, staking out a stand of "conservative realism."

"The war on terror is not over, and America cannot disengage from the world," Paul said. "We need a foreign policy that recognizes our limits and preserves our might, a common-sense conservative realism of strength and action."