It would be a luxury to have the radar system developed by Raytheon and realtime access to U.S. spy satellites to detect Iranian launches.
However, the Israeli timetable for any attack on Iran can not and must not be predicated on the availability of American radar or intelligence. Israel must be prepared to make due with it's home grown radar systems and the home grown Ofek satellite network.
The Israeli decision of if and when to attack Iran can not be held hostage to the prevailing whims of Washington.
Of course, America should support Israeli efforts against Iran, because an Iranian nuke poses a dire threat not only to Israel but to 'the Great Satan' as well. That is, unless America thinks the oft chanted Iranian mantra of 'Death to Israel, Death to the USA' is just for entertainment purposes only.