Israel is integrated into the “war plan for major combat operations” against Iran formulated in 2006 by US Strategic Command (USSTRATCOM). In the context of large scale military operations, an uncoordinated unilateral military action by one coalition partner, namely Israel, is from a military and strategic point almost an impossibility. Israel is a de facto member of NATO. Any action by Israel would require a “green light” from Washington.
An attack by Israel could, however, be used as “the trigger mechanism” which would unleash an all out war against Iran, as well retaliation by Iran directed against Israel.