Buffer state

A buffer state is a lying between two rival or potentially hostile. 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. 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 foreign policy, which distinguishes them from s. The concept of buffer states is part of a theory of the  that entered European strategic and  thinking in the 18th century.

Historic buffer states
Examples of buffer states include:

Americas

 * , created by as a buffer between  and  during, also between  after the.
 * , served as a demilitarized buffer between and the  during the early independence period in South America.
 * , maintained after the end of the in 1870, as a buffer separating Argentina and Brazil.
 * , a established by  in 1732 as a buffer between its other  of North America and.

Asia

 * Multiple buffer states played major role during (66 BC – 628 AD), notably the  and.
 * during and after the, seen by some analysts as a buffer state between the military forces of and  forces in ,  and  fleet in.
 * During, was a pro-Japanese buffer state between the , the , and.
 * , whose king had to surrender his country's hegemony over and  and to grant commercial concessions to France but managed to retain independence as a buffer state between, , and the.
 * was acting a buffer zone between the growing superpower, Empire of Japan and the northern mainland neighbor,.
 * The was a formally independent state created to act as a buffer between  and the Empire of Japan.
 * was a buffer state between the (which ruled much of ) and the  (which ruled much of ) during the  in Asia during the 19th century, with the  later extending the buffer eastwards to the Chinese border.
 * The n nations of, and  were buffer-states between the British Empire and China, later between China and , which in 1962 fought the  in places where the two regional powers bordered each other.
 * , acted as a buffer between the Soviet Union and China until 1991 and currently serves as a buffer between Russia and China.
 * The was a frequently contested buffer between the  (as well as the later ) and the various  and Muslim states.

Africa

 * The served as a buffer state between the, , and  in the 16th century.

Europe

 * before, serving as a buffer between , (after 1871 the ), the  and the.
 * served as a demilitarized buffer-zone between and  during the  years of the 1920s and early 1930s. There were early French attempts at creating the.
 * , between and.
 * and other states between and the  have sometimes been described as buffer states, with reference both to when they were non-communist states before, and to  they were  states after World War II.
 * During the, acted as a buffer state between  and the  blocs after the 1948.
 * has been described by experts such as and  as a buffer state between  and the  bloc, at least up to the  of former President  in February 2014.