Israeli Prime Minister Binyamin Netanyahu cannot risk waiting for much longer.
Iran is very close to having a nuclear weapon.
Netanyahu has a very dim view of Barack Obama. He does not see him as being the strong ally that Israel needs to help fend off a genocidal regime in Tehran.
It is unlikely Obama would act against Iran so close to the election. Mitt Romney might not be able to help until January even if he wins in November. That time frame doesn't work for Israel.
It might be go time in the next 90 days.