The banks behaved irresponsibly because the federal government stood ready to bail them out if they got in trouble. When you don't expect to have to endure the full consequences of irresponsible behavior you are more likely to engage in it.
The same applies to Israel. Would they attack Iran if they thought that they, and they alone, would have to bear the consequences? The US should not be backing the play of any government thereby relieving them of the pain of reckless choices.