The US military has now admitted to bombing Syrian government forces in September, but claims that it was an unfortunate accident.

This happened days after a cooperation deal was cut between the Russians and the US, and it had the effect of torpedoing the deal.

I do not believe that it was a mistake.  I believe that someone in the US chain of command did this deliberately to queer the deal.

Of course, you will never find out who, but you can fire those in the chain of command for incompetence, and that should have been done at the time.