I'm an outsider, with no inside information, just reading the tea leaves, but here's my take on the U.S. and Israeli maneuvering regarding war with Iran. I previously indicated my doubts about the wisdom or effectiveness of a military strike at the present time.
The American and Israeli governments agree on the basic goal -- preventing Iran from having a nuclear weapons capability. They define that goal differently, however, with the Israelis reluctant to let Iran achieve even a theoretical capability to build a weapon and delivery system in less than a year or so and the U.S. government concerned about a tested or at least testable warhead and delivery system. Those differing definitions, of course, lead to much different deadlines for action.
The current Israeli government -- despite warnings from several former high officials in military and intelligence posts -- seems determined to press for military action before the end of 2012. Israeli officials want the United States to act against Iran, or support their actions, or at least not oppose their actions. They may also believe that the Obama administration is more likely to be supportive prior to the November elections because of the continuing strong pro-Israeli support in Congress. [In fact, some Senators are pushing legislation that would adopt the Israeli definition of nuclear capability as official U.S. policy.]
The Obama administration has been using Israeli war talk to leverage support for tougher sanctions by other nations. And sanctions have been tightened, notably by the European decision to halt purchases of Iranian oil by midyear and by U.S. moves against financial institutions linked to Iran. The administration has also built up its military forces near Iran and has reportedly provided additional capabilities to Israel.
American intelligence assessments, however, still view Iranian activities as moving toward a nuclear weapons capability, but lacking a definitive decision to build one. U.S. officials have been traveling to Israel, apparently seeking to reassure the Netanyahu government and also to warn of the consequences of premature military action. They have also gone public with warnings about the broad range of likely Iranian retaliatory acts.
Israeli officials now seem to be pressuring the administration to commit to military action even before Iran has a confirmed weapons program and an imminent warhead. The action-forcing events seem to be the AIPAC convention, where both leaders will speak, and an Oval Office meeting between them early next week.
This is a delicate moment for both nations. If they really want to collaborate and keep up the pressure on Iran, they can easily find public rhetoric to do so. That's the likely U.S. posture. But if the Israelis want to use their election year leverage and threaten Obama, they will likely leak unfavorable reports of private meetings. That would politicize the issue and raise doubts about U.S.-Israeli cooperation on their shared goal.