As far as I know, none.
India
Buddhism was largely (or totally) eliminated from many of the nations that are now Muslim, such as Afghanistan, Pakistan, etc. It was also largely eliminated from India, though some scholars believe that this was mostly the work of Muslims, rather than Hindus.
As Buddhism is in essence the wish or choice to engage with the laws of cause and effect it can never be eliminated. Assuming their was a country with no Buddhists it doesn't preclude that people may begin at any time to follow Buddhist teachings.
No. Unfortunately it is still found in many countries.
Buddhism is present in almost all the countries of the world.
No African countries practice Buddhism as their main religion.
The origin of Buddhism is INDIA.
Buddhism effects the cultures and countries of China, India, the Middle east and many countries in Asia
Buddhism exists in all countries where there is religious freedom.
Buddhism spread to: China Japan Korea Most of Asia. Buddhism spread to: China Japan Korea Most of Asia.
Buddhism originated in India. Buddhism spreaded from there to other countries. It strated around 6 B.c.
Buddhism can be practiced ANYWHERE in the world. It is easier to practice buddhism in the eastern countries however buddhism is now starting to grow in America and other countries over in the west. There is no set place where buddhism should be practiced because it is more of a way of life, not as much a religion.
Generally speaking, it is individuals who follow Buddhism, not countries. However, Buddhism is the state religion of Cambodia and Bhutan, and receives prominent mention in the constitutions of Thailand and Sri Lanka.