

It technically may not even be a breach of international law, since the US is one of the few countries that did not ratify UNCLOS, the law that would apply in international waters. The US was evil for a long time and refused to sign anything that would hold them even symbolically accountable. This did not start with Trump. He just went mask off.
I would love to know as well, so I am slowly reading the UNCLOS treaty as I have time. We have no obligation towards US to not sink their ships, but we may have given promises to other parties of UNCLOS not to attack any ships, even those that did not sign.
It’s like if your promise your wife you will be nice to your mother in law. You did not promise anything to your mother in law and she promised nothing to you, but you are still obligated to be nice to her unless your wife agrees to cancel the promise.
So I don’t know if UNCLOS only deals with not sinking member ships or all ships.
Also, touching US ships is historically very dumb thing to do.