Saying that the awful things he does by choice is actually necessary things that he doesn’t like doing and would stop if he could

Thank goodness it wasn't my argument.

the fact that presidents have the power to change longstanding foreign policy

correct. And my response was...? Let me restate it because maybe it wasn't clear:

What a president can do and what a president ought to do in changing policy are two different things and bringing up the fact that change was able to occur in a place with low stakes (cuba: very low stakes) is not equivalent to the policy change that needs to occur in Israel (very high stakes). It's not apples to apples, is it?