Have any of those wars come close to actually threatening the state of Israel itself, rather than just their control over territories they’d occupied from someone else? In any case, you’re also making a false assumption that ending US military aid to Israel leaves it conventionally defenseless, or that US weapons have to be stopped from going there in perpetuity. Israel has both a domestic arms industry and other countries it could acquire weapons from, it would just be at increased difficulty and expense. Further, when the objection to sending US arms there is that they are using them to commit genocide, that objection would naturally end should Israel cease those operations.

The point is not “Israel should have nothing left but the nukes, because they can just use those”, but rather “Israel’s nukes mean that a full scale invasion of the country is not likely, so we have room to revoke our current military assistance in order to pressure them to behave better, without much risk of destroying them in the meantime by doing so.”