Read moe>http://online.wsj.com/article/SB1000...toWhatsNewsTopBy ADAM ENTOUS,JULIAN E. BARNES and JAY SOLOMON
WASHINGTON—U.S. defense leaders are increasingly concerned that Israel is preparing to take military action against Iran, over U.S. objections, and have stepped up contingency planning to safeguard U.S. facilities in the region in case of a conflict.
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.
Stepping up the pressure, Mr. Obama spoke by telephone on Thursday with Israeli Prime Minister Benjamin Netanyahu, and U.S. Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, will meet with Israeli military officials in Tel Aviv next week.
The high-stakes planning and diplomacy comes as U.S. officials warn Tehran, including through what administration officials described Friday as direct messages to Iran's leaders, against provocative actions.