What did Donald Trump do today?

He offered a tactical excuse for his strategic problem in Syria. 

Reacting to news that the Assad regime was using the Shayrat airbase less than a day after Trump ordered a missile strike, Trump took to Twitter to explain why the runways had been left intact: "The reason you don't generally hit runways is that they are easy and inexpensive to quickly fix (fill in and top)!"

Trump is correct that runways are relatively cheap to repair. However, the statement implies that the United States would not be able to continually prevent the Assad regime from repairing them, at Shayrat or any of the dozen other bases from which Assad might launch airstrikes. This is false.

The actual reason that that Trump left Assad with a functional airbase is that the incredibly  complicated geopolitics of the situation--in which the United States is a de facto ally of Russia and hence the Assad regime--did not permit him to meaningfully degrade the regime's capabilities. In fact, Trump was powerless even to mount a surprise attack. Keeping Russian soldiers safe meant warning Russia, which meant warning Assad.

So what?

• It's bad if a military action ends up calling attention to the limits of what the US can do.

• Trump should probably be more concerned about what led Assad to use chemical weapons at this particular moment than about whether people are making fun of him on Twitter.