The American administration is preparing for the possibility of an Iranian response in the coming days, with two security officials and a White House senior official telling NBC News that the next 48 hours are considered especially critical. According to the sources, it is unclear whether Iran will choose to strike American targets overseas, within U.S. territory or both simultaneously. Two sources familiar with military planning reported earlier this week that Iran has contingency plans to attack American bases and assets in the Middle East if necessary, although at this stage there are no signs of immediate preparations for such action.