The Dhamma ebbs and flows everywhere in the world. It's much like a garden of flowers, some flowers open at certain seasons, other at another time. By the time your roses come out, your tulips are withering.
(I'm not a gardener, so I may have got my analogy completely wrong)
At the moment the Dhamma is ebbing in Thailand. There are certain monasteries in which the Vinaya is upheld very strictly and meditation is of paramount importance. For example monasteries of the Ajahn Chah lineage, and monasteries of the Ajahn Mun lineage to name a few.
From what I've gathered from reading Peter Robinson's book Phra Farang, the majority of Monks in Thailand don't meditate and many do not have a firm understanding of the Buddha's teachings. But this is not the first time this state of affairs has occurred. In 1833 Prince Mongkut the son of King Rama II founded the Dhammayuttika Nikaya (or simply the Dhammayut) order in Thailand, as a reform movement which seeked to follow the Vinaya code more strictly and adhere to the Buddha's teachings. So they were facing the same problem over a hundred and fifty years ago.
Ebbs and flows.
The important thing is that the Dhamma is still readily available, and there are still many learned practitioners in Thailand, and elsewhere in the world.
"But, Udāyi, let be the past, let be the future, I shall set you forth the Teaching: When there is this this is, with arising of this this arises; when there is not this this is not, with cessation of this this ceases." - Majjhima ii,32
Nanavira Thera's teachings - An existential approach to the Dhamma:http://bit.ly/LDsGHg