A nuclear Iran is not in America's interest, and the USA is pursuing a halt to Iran's nuclear program because of its own national goals. Israel has common cause, but it is not telling America what to do. Anyway, it is the Arabs that got you bombing Libya so they wouldn't have to, and would be quite pleased if you got involved in Syria as well.
Iraqi police fire tear gas as thousands of protests burst into Green Zone, storm Parliament (AP)
from the article: Israel Vice PM: Military strike can hit all of Iran's nuclear facilities