Which brings us to the consequential question: What’s the proper U.S. response?

It can’t be the usual Trumpian cycle of bluster and concession. Neither can it be the liberal counsel of feckless condemnation followed by inaction. Firing on unarmed ships in international waters is a direct assault on the rules-based international order in which liberals claim to believe. To allow it to go unpunished isn’t an option.

What is appropriate is a new set of rules — with swift consequences if Iran chooses to break them. The Trump administration ought to declare new rules of engagement to allow the Navy to engage and destroy Iranian ships or fast boats that harass or threaten any ship, military or commercial, operating in international waters. If Tehran fails to comply, the U.S. should threaten to sink any Iranian naval ship that leaves port.

If after that Iran still fails to comply, we would be right to sink its navy, in port or at sea. The world cannot tolerate freelance Somali pirates. Much less should it tolerate a pirate state seeking to hold the global economy hostage through multiplying acts of economic terrorism.