You maybe right. I wouldn’t put anything past this administration.
I can't imagine Obama ever giving the order to sink, shoot at or in any way harm an Iranian ship... I just don't see that happening. But... I can imagine him asking the Saudis to refrain from sinking or shooting at the Iranian ships "in the interest of peace".
I hope I'm wrong, but I do believe that our presence is actually going to make it safer for these ships to reach their destination.