What did Donald Trump do today?

He had a variety of reactions to the news that China had seized and then agreed to return a US Navy research robot.

On Friday, China seized a submersible drone used for oceanographic research in what China regards as its territorial waters. Trump's first tweet, in which he angrily condemned the "unprecedented" seizure, came shortly before China arranged with the Obama administration to return the drone. The second, which came after that agreement, said that the US should tell China to keep it. 

All the same, Trump claimed credit for the return through a spokesperson.

It is not clear if Trump understands that the seizure was probably intended as a provocation in response to his protocol-breaking public acknowledgment of the Taiwanese president as a head of state.

Why should anyone care?

• It's wrong to take credit for things you didn't do.

• It is a very bad sign if Trump thinks this was resolved by an angry tweet.