U.S. stepping up contingency plans due to fear of Israeli attack on Iran

President Barack Obama, Defense Secretary Leon Panetta and other top officials have delivered a string of private messages to Israeli leaders warning about the dire consequences of a strike. The U.S. wants Israel to give more time for the effects of sanctions and other measures intended to force Iran to abandon its perceived efforts to build nuclear weapons…

The U.S. military is preparing for a number of possible responses to an Israeli strike, including assaults by pro-Iranian Shiite militias in Iraq against the U.S. Embassy in Baghdad, according to U.S. officials.

The U.S. believes its embassy and other diplomatic outposts in Iraq are more vulnerable following the withdrawal of U.S. forces last month. Up to 15,000 U.S. diplomats, federal employees and contractors are expected to remain in Iraq.

In large measure to deter Iran, the U.S. has 15,000 troops in Kuwait, and has moved a second aircraft carrier strike group to the Persian Gulf area.

It has also been pre-positioning aircraft and other military equipment, officials say.