I believe you are correct, sphinx. The United States has done quite a bit to destroy its own merchant marine. Taxes, regulations, etc.
No matter. If you want US Navy protection, fly the US flag and jump through all the hoops. I certainly wouldn’t blame a ship owner for deciding not to go in that direction. US regulations can be burdensome. But there should be no free lunch. Enough of other nations skating on Uncle Sam’s dime.
In a way, it’s like house insurance. Buy it, or take your chances.
Iran funds these idiots, right? That should suggest a way to get it to stop, if they don’t have the toys they can’t play in the sandbox.
I would just send Iran a note saying next one is on you, and we will escalate the damage each time until it stops.