What would happen if the US stopped supplying Ukraine?
Would both places, Ukraine and Israel suffer the same outcome?
I suppose it's a question of how indispensable U.S. military aid is, in either situation. I suppose one could do a search to find a list of countries sending aid to Ukraine and Israel, look at the numbers and estimate the impact the removal of U.S. aid might have. I think Ukraine gets aid from numerous other countries, so the loss of U.S. aid may not have as steep an impact as it might have in Israel.
There may also be a political impact and fallout if the U.S. reverses policy and decides to not send supplies to either country. If we stop supplying Ukraine, then other countries in our alliance could see that as dishonorable, although that might also cause them to increase their own supply of aid to compensate for the loss of U.S. aid.
The other side of the question is what the other side might do. Could Putin be persuaded to stop the invasion of Ukraine in exchange for an agreement to end U.S. military aid? Could Hamas be persuaded to stop attacking Israel in exchange for an agreement to end U.S. military aid? Could either of them be expected to honorably fulfill such an agreement?