GOP challenger Mitt Romney accuses Obama of being weak on Iran. He says the U.S. needs to present a credible threat of military action and should work with insurgents to bring down Iran's government, not coax it into better behavior through engagement. His aides have spoken of the need to prevent Iran from even acquiring the capability to develop nuclear weapons, a criterion that could lower the bar for a military response. Romney's Iran policy dovetails with his argument that he'd be a sturdier ally of Israel. He says he'd support the Jewish state if it decides to attack Iran. In the last presidential debate, however, he said sanctions were working and stressed the need for "peaceful and diplomatic" approaches, saying war should only be considered when all else fails.