Bhutan is a landlocked country in South Asia settled between powerful neighbors, China and India. Bhutan is mostly mountainous and controls several key Himalayan mountain passes. The government system is a constitutional monarchy; the chief of state is the king, and the head of government is the prime minister. Bhutan has a largely traditional economic system in which the allocation of available resources is made on the basis of inheritance and primitive methods. Bhutan relies heavily on India for monetary and trade links. Bhutan is a member of the South Asian Association for Regional Cooperation (SAARC).