Thailand is writing a new constitution. The country is 90% Buddhist. The Muslim minority is getting increasingly militant. The Buddhist leadership pressed the constitution writers to declare Buddhism the national religion. To the consternation of the monks, the constitution writers voted against it 66 - 19. The Constitution Drafting Assembly's spokesman said "we will lose more than we would gain from it." And quite right, too.
The days of nation-state religions are over. Declaring the majority faith to be the national religion now only makes the minorities more oppressed and more resistant. It is a particularly bad idea to make Muslims more resistant at this moment in history. Buddhism has thus far been able to avoid developing a violent fundamentalist wing, at least outside of Sri Lanka, which is a good thing, especially in the religious tinderbox of South Asia.
My advice to the Buddhist monks in Thailand: insist on a freedom of religion clause in the constitution. Then go evangelize.