McChrystal left Obama no choice.
It's an abrupt and disappointing end to what appears to be an otherwise exemplary military career. I do, thought, believe there are a number of lessons that can be gleaned from this unfortunate turn of events.
1) Once a star appears on your shoulders, everything you do and say will be subjected to the harsh light of bureaucratic and public scrutiny. That scrutiny exponentially increases with each additional star. This multiplies astronomically when one becomes the field commander of a lingering, multi-year war. Act accordingly, 24/7/365.
2) Soldiers are human, too. Off-duty, they drink, use course language, act sophomoric and immature, have issues with authority, believe they're smarter than their superiors, are disdainful of self-important politicians, have strong political views and share them with their peers and friends in discussions that often include the aforementioned course language.
3) The President's perception problem permeates the military as thoroughly as it does the international arena.
4) Loose lips sink ships. And decades-long military careers. Take the Go-Go's admonition to heart and keep your lips sealed.
5) Unlike Dr. Hook, generals should never, ever long to appear on the cover of the Rolling Stone.