Donald Trump's period of mildly restrained behavior appears to be coming to a bitter end — in spectacular fashion. Trump suffered a string of humiliations on Wednesday when he was forced to sign a Russia sanctions bill that he didn't want to sign and was then called out for his “impotence” by Russian Prime Minister Dmitry Medvedev.

As if his weak signing statement hadn't gotten the message across clearly enough, Trump engaged in a little public diplomacy with Russian dictator Vladimir Putin on Thursday morning by attacking Congress:

Perhaps Trump thought holding a boombox aloft in the rain outside the Kremlin would take him away from his golf game for too long. But don't worry, I'm sure Putin got the message.

This tweet might seem, now, like just another sign of a weak and unhinged president, but it could take on greater significance down the road if Special Counsel Robert Mueller's investigation continues in the direction it's headed. Tweets like this help to establish a pattern of behavior that could demonstrate and corroborate other evidence of Trump's complicity with Russia.

So keep tweeting, Donald. Putin is listening, but so is Robert Mueller.

Please note: This is a commentary piece. The views and opinions expressed within it are those of the author only and do not necessarily reflect the editorial opinion of IJR