OK, what IS going on?
There has been a political stalemate for the past 6 months or so. The (former) prime minister has made a lot of enemies and there have been a few attempts to get him kicked out of office legally. He has refused to give up power and instead lashed out against anyone who says anything bad about him.
About two weeks ago, there was an 'assassination attempt' against the PM. It appears to have been a setup by the PM in order to use it as an excuse to reshuffle the military and put his cronies into power (Sondhi was going to be one of the ones kicked out). After this, the (former) prime minister went on a public rampage attacking the military every chance he got.
This greatly pissed off the military since they saw it as a trick for him to stay in power. Of course, I don't know all the details, but this led to the coup. The (former) PM, in NY, tried to remove Sondhi from power, and Sondhi checkmated him by shutting him down.
With the (former) Prime Minister out of the picture, the heads of the military and police (all Buddhist except Sondhi) have met with the King (Buddhist) and prepared the way to restore civilian leadership and new elections.
That is it in a nutshell.