Historically, maybe a bit surprising for some, Thailand has a negative trade balance with the rest of the world, most of the time. If a positive trade balance is present, it remains relatively small (see period between 2001-2010)
Of course, if not for crude oil imports, the trade balance would be positive all the time. This applies to a lot of other countries as well.
Notice the striking trade deficits in the 1995-2000 period. This is around the 1997 Asian economic crisis, which started off in Thailand. I remember reading at the time preceding the crisis, that the country was importing a lot of 'capital goods', which was reportedly a good thing. Obviously too much of a good thing, turned out to be bad at the time.
In 2014, there was a tiny trade deficit recorded of about 380 million U.S. Dollar