@rameshgupta of course it is not a carte blanche to commit war crimes, which have not been alleged, nor an immunity from or lack of commitment to international law. but it is absolutely one-way in terms of the US backing Israel in an existential war not of its own choosing. Israel's own responsibilities, the strategic benefits provided in return, are separate.
the weapons in question do not necessarily violate humanitarian considerations. if they are configured to detonate underground they tend to spare life, as long as their path is between buildings, which can be done. this allows targeting the tunnel infrastructure more directly to sever strategic lines of defense before an assault. they are used by the US as well. using less precise weapons would be deadlier to civilians, not safer.
the funds were already appropriated by Congress, so his constitutional authority to do this is unclear, leaving him subject to impeachment, not to mention the "high crime" of abandoning American hostages.