Mattis's resignation letter is a screaming siren

It’s getting real. As in really dangerous. This is not a drill.

Here are the key paragraphs:

Note that he very specifically cites the national security necessity of working with traditional allies, and just as specifically cites the danger as China and Russia try to impose authoritarian rule over other nations at our nation’s expense. And it is only directly after those paragraphs that he explicitly states that he and Trump have differing views on those and other subjects.

To be clear: The secretary of defense is explicitly, publicly warning the nation and the world that Trump is operating in service to China’s and Russia’s authoritarian agendas. I used to say it was hiding in plain sight. That no longer applies. It’s not even pretending to hide anymore.