WASHINGTON  — President Barack Obama is casting the Iran talks as part of a broader foreign policy doctrine that sees American power as a safeguard that gives him the ability to take calculated risks.

Obama staunchly defended a framework nuclear agreement with Iran as a “once-in-a-lifetime opportunity” to prevent a bomb and bring longer-term stability to the Middle East.

He insisted the U.S. would stand by Israel if it were to come under attack, but acknowledged that his pursuit of diplomacy with Tehran has caused strain with the close ally.

“It’s been a hard period,” Obama said in an interview with New York Times columnist Thomas Friedman. He added that it is “personally difficult” for him to hear his administration accused of not looking out for Israel’s interests.

“We are powerful enough to be able to test these propositions without putting ourselves at risk,” he said, citing his overtures to Cuba and Myanmar as other examples of his approach.

The president’s comments come in his seventh year in office and days after the U.S. and other world powers reached a tentative agreement to curb Iran’s nuclear program in exchange for sanctions relief. The framework cleared the way for negotiators to hammer out technical details ahead of a June 30 deadline for a final deal.