What did Donald Trump do today?

He gave Russia a green light to ignore sanctions against its oil industry.

In what even straight news reporting is calling a "stunning reversal" of US foreign policy, Trump announced today that he had reached a deal with Vladimir Putin to import up to 3 million tons of diesel from Russia.

Trump may have believed this would convince voters he was taking action to lower the record-high diesel prices that are driving up inflation. But even by his standards, this is a bizarre thing to do, for a number of reasons:

• The United States already has all the diesel it can use. There is no supply shortage in the United States, which produces more diesel than it consumes and exports the rest. In fact, it exports the same amount of diesel in 18 days that Trump says Russia will sell to the United States over an unspecified number of months.

• Prices won't go down because the supply isn't increasing. Diesel is a globally traded commodity, with highly efficient markets. That means that its price is a function of supply and demand. There's no indication that the Putin regime is increasing its production, or even that it could if it wanted to. That means that every barrel imported from Russia will simply free up another barrel to go elsewhere at the same market price.
  
  (This is generally taught in the first week of economics courses at business schools like the one Trump has a diploma from.)

• The amount is miniscule. Even if there were some economic advantage to Russian diesel, the amount in question is a tiny fraction of US daily demand: about 23 million barrels, or barely one week's supply. That may be why Trump chose to express it in tons rather than gallons, to make it seem like a larger quantity than it really is.

But Trump doing business with Russia has consequences that go well beyond the financial. By doing so, Trump is violating the spirit of a law he just signed, under pressure, sanctioning Russia and Putin personally and punishing countries that buy Russian oil and gas. Trump, who is personally and politically beholden to Putin, has been pursuing a totally different Russian foreign policy than the rest of the United States for his whole presidency.

Ukrainian President Volodymyr Zelenskyy responded bluntly, calling Trump "dishonest" and "weak" and pointing out that Trump is now directly funding the enemy that the United States has committed to helping Ukraine defeat. 

At this very moment—while our team is speaking with the American team in Florida—the President of the United States is talking to the Kremlin leader, the leader behind this war and this aggression, and is reaching an agreement allowing Russia to export diesel. This means additional funds for the war, additional funds to fuel the suffering inflicted upon us. Undoubtedly, this only emboldens Putin and enables them to continue fighting. It is happening right now, just as we are discussing peace: America is allowing Russia to export diesel. This means millions, billions. Ultimately, it all goes towards the war against people, against Ukraine—against all of us. I believe our team is simply being used as a smokescreen. This is certainly dishonest; it is certainly not how partners should act. And, in my view, it is a weak decision—sadly, a weak decision made by strong partners.

This isn't even the first time this year that Trump has undermined US foreign policy by buying oil from a hostile nation. In March, in another desperate attempt to avoid the blame for skyrocketing gas prices, he canceled oil sanctions on Iran three weeks into the war.

Why does this matter?

• This would be pathetic and desperate even if it could actually lower diesel prices. 

• The only reason for a president to fund nations hostile to the United States is incompetence, or because he doesn't care that they're hostile to the United States.