And now Sir Kim has done the 'right thing' for Anglo-American relations, demonstrating that he isn't stupid and in a truly intelligent and diplomatic act resigned his position not because of Trump's childish tantrum, but for future relations between the countries. Showing an understanding far beyond the ken that Trump could ever have.
Ken - Scottish word meaning a deep understanding and or knowledge.

In a couple of weeks Boris will more than likely be PM and he is supporting Trump in this little spat so I think sir Kim will shortly be moved from Washington.

Well put ~