As Houthi attacks set tankers alight in the Red Sea on July 24, Trump posted a reassurance about the bill: the damage, he wrote, 'will be paid for by Iranian Money that the United States has in its possession, and controls,' which he called 'the fair and equitable thing to do' [1].

The promise rests on a fund that is mostly not in American hands. Iran has an estimated $100 billion or more in frozen assets, but the bulk of it sits abroad - roughly $20 billion in China, and billions more in Iraq, Qatar, India, the European Union and Japan [2]. Only about $2 billion is held in the United States, and historically Iran has been able to reach only about half of its frozen funds at best [2].

Set that $2 billion against the losses it is supposed to cover. A single very large crude carrier plus a two-million-barrel cargo runs into the hundreds of millions of dollars. The account Trump names would not settle even one severe loss, let alone a running campaign of attacks [2].

The legal claim is the weaker half. A president cannot confiscate a sovereign state's assets and hand them to private claimants by announcement; that takes a judgment. Iran's Foreign Minister, Abbas Araghchi, called the threat an 'incendiary precedent' that endangers 'everyone's financial security globally' - the warning being that if Washington can seize sovereign reserves on a social-media post, no nation's foreign-held funds are safe [1].

The statement is built to sound like a matter settled: Iran will pay, the money is already ours. The money is mostly somewhere else, and the authority to take even the small part that is here does not come from a post [1][2].