The main problem for the Thai Baht is that it was fixed to the dollar. This seems like a good idea, especially in the short term, but when you think about it a bit, you’ll see that when an imbalance occurs, instead of the market moving slowly in tiny increments, the adjustment is a crisis. This is basically what happened. Instead of the baht devaluing slowly over time, slowing the economy over a period of years, the pain all came at once in a matter of days.
This is exactly why China must start to loosen it’s currency controls now. If an imbalance were to occur, it could be a global disaster.