In a preview of campaign refrains to come, prominent conservatives are saying President Obama’s foreign policy is hurting our allies and helping our enemies.

The “Obama as Carter” motif dominated the conservative Foreign Policy Institute’s annual conference, held in Washington Monday and Tuesday, with GOP headliners making unflattering comparisons to the 39th president to warn of a decline in U.S. international standing.

Obama’s stance on the presidential crisis in Honduras, willingness to engage Iran in nuclear talks and decision to scrap the Bush administration’s missile defense plans in Eastern Europe were popular targets...