I think the presumption is that the U.S. would (have to) respond differently to an attack on a U.S.-flagged vessel compared to an attack on anyone else. So, not

I think the presumption is that the U.S. would (have to) respond differently to an attack on a U.S.-flagged vessel compared to an attack on anyone else. So, not a question of defense, but of the proportionality of the post hoc response.