On Dec. 27 last year, Gen. Prayuth Chan-ocha, Thailand's powerful army chief, stood before a crowded news conference and stunned the beleaguered government of Prime Minister Yingluck Shinawatra by saying he would not rule out military intervention to resolve a deteriorating political crisis.

Prayuth said "the door was neither open nor closed" when he was asked whether a coup would happen. "Anything can happen."

It was a marked shift from the strong coup denials the armed forces had routinely made up until then.