Within limits,of course.
If Israel deemed nuclear weapons necessary for the continued survival and safety of its people and an American President stood in the way,you are not suggesting actions against the U.S. Constitution would be justified in securing nuclear weapons for Israel, are you?
"...and an American President stood in the way..."
i'd eat my yarmulke if that ever happened.
and, incidentally, on the issue of the american constitution: doesn't apply to Israel, or to any nation other than our own. We could decry all day long any actions any foreigners undertake against it, but, as a practical matter, our ability to do something about it comes down to a question of force. As do, ultimately, all relations between nations. "State of nature' and all that.
With that said, I doubt very much that israel would strike against its only quasi-reliable ally, regardless of circumstances, even as we would not act against our only ally in the mid-east.
It seems to me that Israeli violations of the law of nations bother you quite a bit. tell me, do incursions by Pakistanis into india bother you as much?