What did Donald Trump do today?

He floated the idea of temporary undoing less than a week of the inflation he's caused.

Rising gasoline prices are one of the most visible effects of Trump's disastrous war with Iran. Most Americans buy gas regularly, and the prices are prominently displayed—and for Americans who can't charge the cost of their travel to the taxpayers, it's usually a major household expense.

The fact that Americans feel changes in the price at the pump so clearly, even though the cost of filling up a tank isn't necessarily the most severe problem that Iran's ongoing successful blockade of the Persian Gulf will cause, makes it a political crisis for Trump. And that is why today he proposed pausing collection of the 18.4-cent-per-gallon fuel tax.

The funds raised from that particular tax are earmarked for transportation construction projects, so that the heaviest users of roads are also contributing the most to their maintenance. There's no free lunch: every dollar lost to a gas tax holiday would either have to come from other revenue sources, or through canceled maintenance on an already aging and rickety highway infrastructure. 

But the real problem with Trump's idea is how little it would offset the damage done by the Iranian blockade that he instigated. Even assuming that wholesalers, resellers, and retailers all dropped their prices the full 18.4 cents—and there is no guarantee they would—it would only cancel out about five days of recent gas price inflation. 

A better and more permanent solution would be a resolution of the conflict, but Trump seems both unable and unwilling to move towards that goal. Unable, because Iran has a much stronger negotiating position in the short term: its authoritarian government's control has been strengthened by the war, and it had already been cut off from global trade even before hostilities began. Iran's ruling regime has shown no interest in giving Trump in easy off-ramp. And unwilling, because there is essentially no path forward for Trump that doesn't end in utter humiliation for a man who is incapable of admitting even trivial, harmless mistakes.

And unfortunately for Americans and the rest of the world economy, even a quick end to the conflict and the sudden reopening of the Persian Gulf wouldn't avoid serious long-term consequences. Global oil reserves are approaching critical levels, after which it won't be possible to put any brakes on the upward spike in prices. Production has already shut down in many Gulf oil fields, and capped wells can't be reopened quickly or cheaply. Trade disruptions have already driven the price of basic feedstocks like plastics, sulfur, nitrates, helium, and aluminum, and that in turn has already led to likely permanent price increases in sectors ranging from agriculture to computing to manufacturing in general.

The federal gas tax is set by law and Trump has no authority to order it paused.

Why does this matter?

• Donald Trump's pride is less important than the American and world economy. 

• No remotely competent president would ever have let the situation get this bad in the first place. 

• Shifting money around to make it look like things aren't so bad didn't work for Donald Trump's private businesses, and it won't work here. 

• Americans generally like having food to eat even more than they like having gas for their cars.