According to Wikipedia,
Bhutan has diplomatic relations with 52 states and the European Union.
In 1971, sponsored by India, Bhutan began to develop its foreign relations by joining the United Nations, though it has no diplomatic relations with any of the permanent members on the UN Security Council. In 1981, Bhutan joined the International Monetary Fund and World Bank, followed by the World Health Organization and UNESCO in 1982. It is also an active member of SAARC. Bhutan is currently a member of 45 international organizations.
Why doesn't Bhutan have diplomatic relations with most countries in the world?