What did Donald Trump do today?

He invited the British government to join him in saber-rattling over Syria, which pointedly declined.

Seeking international support and, perhaps, a way to save face as the intractable nature of the Syria situation dawns on his administration, Trump called British prime minister Theresa May today. She declined to endorse further US military action in advance. 

Allies of the United States, including Britain and Germany, had expressed guarded support for the first, carefully limited strike on a Syrian airbase that figured in last week's chemical weapon attacks. Since then, the Trump administration has tried to walk a very fine line between maintaining an aggressive posture and alienating its partners in the fight against the Islamic State, which include Russia and (indirectly) the Assad regime itself. 

Trump administration officials have been at pains to appear to disapprove of Assad, while (mostly) stopping carefully short of saying they want him deposed, which would embroil the United States even further in an incredibly complicated and bloody civil war, and which would almost certainly work to the benefit of the Islamic State. This is complicated by the fact that Trump was, as of a week ago, a staunch non-interventionist where Assad was concerned--which Assad seems to have taken as tacit permission to resume chemical weapon attacks. Today press secretary Sean Spicer seemed to suggest that the use of barrel bombs would provoke another US response, but Assad uses barrel bombs against civilians on a regular basis, and Spicer's statement was quickly walked back. 

What's so bad about this?

• It's bad if the United States' closest military ally lacks faith in the president's judgment.