He does not matter. Argentina has decided to move away from one path and go for another which includes being part of the american empire. 

If you are part of the american empire, you are aligned in their "foreign policy" and you support your allies.  So Israel in this specific scenario. 

You don't, then you will suddenly not be in charge very soon. 

Every other consideration is irrelevant.

Obviously Milei per se, or what he really thinks, what he says etc... is also completely irrelevant.