Buffer state

A **buffer state** is a country lying between two rival or potentially hostile greater powers. Its existence can sometimes be thought to prevent conflict between them. A buffer state is sometimes a mutually agreed upon area lying between two greater powers, which is demilitarized in the sense of not hosting the military of either power (though it will usually have its own military forces). The invasion of a buffer state by one of the powers surrounding it will often result in war between the powers.

Research shows that buffer states are significantly more likely to be conquered and occupied than are nonbuffer states. This is because "states that great powers have an interest in preserving—buffer states—are in fact in a high-risk group for death. Regional or great powers surrounding buffer states face a strategic imperative to take over buffer states: if these powers fail to act against the buffer, they fear that their opponent will take it over in their stead. By contrast, these concerns do not apply to nonbuffer states, where powers face no competition for influence or control."

Buffer states, when authentically independent, typically pursue a neutralist foreign policy, which distinguishes them from satellite states. The concept of buffer states is part of a theory of the balance of power that entered European strategic and diplomatic thinking in the 18th century.

### Americas

* Bolivia, created by Gran Colombia as a buffer between Peru and Argentina during Upper Peru's question, also between Chile after the War of the Confederation .
* Uruguay, served as a demilitarized buffer between Argentina and the Empire of Brazil during the early independence period in South America.
* Paraguay, maintained after the end of the Paraguayan War in 1870, as a buffer separating Argentina and Brazil.
* Georgia, a colony established by Great Britain in 1732 as a buffer between its other colonies along the Atlantic coast of North America and Spanish Florida.

### Asia

* Multiple buffer states played major role during Roman–Persian Wars (66 BC – 628 AD), notably the Lakhmids and Ghassanids.
* North Korea during and after the Cold War, seen by some analysts as a buffer state between the military forces of China and U.S. forces in South Korea, Japan and U.S. fleet in Taiwan.
* During World War II, Manchuria was a pro-Japanese buffer state between the Empire of Japan, the Soviet Union, and Republic of China.
* Siam, whose king had to surrender his country's hegemony over Laos and Cambodia and to grant commercial concessions to France but managed to retain independence as a buffer state between British Raj, British Malaya, and the French Indochina.
* Korean Empire was acting a buffer zone between the growing superpower, Empire of Japan and the northern mainland neighbor, Russian Empire.
* The Far Eastern Republic was a formally independent state created to act as a buffer between Bolshevik Russia and the Empire of Japan.
* Afghanistan was a buffer state between the British Empire (which ruled much of South Asia) and the Russian Empire (which ruled much of Central Asia) during the Anglo–Russian conflicts in Asia during the 19th century, with the Wakhan Corridor later extending the buffer eastwards to the Chinese border.
* The Himalayan nations of Nepal, Bhutan and Sikkim were buffer-states between the British Empire and China, later between China and India, which in 1962 fought the Sino-Indian War in places where the two regional powers bordered each other.
* Mongolia, acted as a buffer between the Soviet Union and China until 1991 and currently serves as a buffer between Russia and China.
* The Ancient Kingdom of Armenia was a frequently contested buffer between the Roman Empire (as well as the later Byzantine Empire) and the various Persian and Muslim states.

### Africa

* The Saadi Sultanate of Morocco served as a buffer state between the Ottoman Empire, Spain, and Portugal in the 16th century.

### Europe

* Belgium before World War I, serving as a buffer between France, Prussia (after 1871 the German Empire), the United Kingdom and the Kingdom of the Netherlands.
* The Rhineland served as a demilitarized buffer-zone between France and Germany during the inter-war years of the 1920s and early 1930s. There were early French attempts at creating the Rhineland Republic.
* Qasim Khanate, between Muscovy and Kazan Khanate.
* Poland and other states between Germany and the Soviet Union have sometimes been described as buffer states, with reference both to when they were non-communist states before World War II, and to when they were communist states after World War II.
* During the Cold War, Yugoslavia acted as a buffer state between NATO and the Warsaw Pact blocs after the 1948 Tito-Stalin split.
* Ukraine has been described by experts such as John Mearsheimer and Stephen Walt as a buffer state between Russia and the NATO bloc, at least up to the ousting of former President Viktor Yanukovych in February 2014.