When Presidents tweet

Several American sites are noting that Trump's tweet re North Korea:

While I greatly appreciate the efforts of President Xi & China to help with North Korea, it has not worked out. At least I know China tried!

 is dangerously ambiguous.  As New York Magazine writes:

But if Trump’s tweet is just mindless bluster, that hardly makes it less unnerving. In their joint military exercises, the United States and South Korea have rehearsed preemptive strikes against North Korea, ones designed to kill Kim Jong-un before he has a chance to press the proverbial button. Arms-control expert Jeffrey Lewis has warned that the implication of these exercises aren’t lost on Pyongyang: Kim knows “he has to go first, if he is to go at all.”

Just because savvy news consumers in the United States are comfortable assuming that Trump is merely talking trash doesn’t mean that North Korea is. In April, the president suggested that the day Beijing’s efforts to rein in Pyongyang failed would be the day that America took action against Kim Jong-un’s regime.

“Well if China is not going to solve North Korea, we will. That is all I am telling you,” Trump told the Financial Times.

The fact that the American president is an emotionally volatile reality star — who publishes his foreign-policy musings directly to the internet — has always been dangerous. In the context of a military standoff with a nuclear-weapons state, it may prove fatally so.

They are right - and you would have to be completely foolish (as Trump supporters are) not to see the impropriety and danger in this idiot President tweeting to the world.