In reality, Israel is unlikely to launch any attack without the support of the United States, which could easily be drawn into the regional conflict an air strike would trigger. Like the Israeli military establishment, the Pentagon opposes any such venture — and it’s hard to imagine President Obama signing on. If he acts in the coming weeks or months, Netanyahu would risk a rupture in the alliance that is the ultimate guarantor of Israeli security.
The new burst of speculation, like those before it, does serve a couple of purposes for Israel, however. It refocuses attention on the Iranian threat, and takes it away from the Palestinian bid for statehood at the United Nations; it raises the pressure on the United States and its allies to increase sanctions and other nonmilitary pressure on Tehran.