they can but biden / usa got extremely upset when israel was attempting to do exactly that. how where they attempting? for like 2 weeks they were preventing anyone from going into gaza including aid and they cut off the water and electricity. if us gave them the greenlight to slaughter all of them and commit a true genocide then i think they would do it.  just doing that would be sufficient enough to kill most of them. they do have an insane number of options to chose from to kill all of them off including chemical weapons.
Netherlands