A buffer state is a country lying between two rival or potentially hostile great 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.
^Pholsena, Vatthana (2007). LAOS, From Buffer State to Crossroads. Silkworm Books. ISBN978-9749480502.
^Macgregor, John (1994). Through the Buffer State : Travels in Borneo, Siam, Cambodia, Malaya and Burma. White Lotus Co Ltd; 2 edition. ISBN978-9748496252.
^Alan Wood, "The Revolution and Civil War in Siberia," in Edward Acton, Vladimir Iu. Cherniaev, and William G. Rosenberg (eds.), Critical Companion to the Russian Revolution, 1914-1921. Bloomington, IN: Indiana University Press, 1997; pp. 716-717.
^George Jackson and Robert Devlin (eds.), Dictionary of the Russian Revolution. Westport, CT: Greenwood Press, 1989; pp. 223-225.
^ abcWalt, Stephen M. (2 September 2014). "History Shows Caution Is the Best Approach for Foreign Action". The New York Times. Retrieved 2015. Instead of rushing to back the demonstrators who ousted the former president, Viktor Yanukovych, the United States and its European allies should have worked cooperatively with Moscow to craft a deal that would have preserved Ukraine's status as an independent but neutral buffer state.