Separate peace

The phrase "separate peace" refers to a nation's agreement to cease military hostilities with another, even though the former country had previously entered into a military alliance with other states that remain at war with the latter country. For example, at the start of World War I (1914–1918), Russia was a member, with the United Kingdom and France, of the Triple Entente, which went to war with the Central Powers formed by Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria. After the fall of Russian monarch Nicholas II and the rise to power of the Bolsheviks, Russia defaulted on its commitments to the Triple Entente by signing a separate peace with Germany and its allies in 1917. This armistice was followed on 3 March 1918 by the formal signing of the Treaty of Brest-Litovsk.

It is customary in cases of war waged by several allies to conclude agreement or declaration by all belligerents on the same side not to conclude a separate peace with the opposing camp. An example of such an undertaking was included in the alliance treaty concluded between the Papal States, the Duchy of Burgundy and the Republic of Venice, concluded in Rome on Oct. 19, 1463. The parties undertook to launch a crusade against the Turks and to refrain from making peace with the Sultan without the consent of all three parties. Such was the case during the First World War and Second World War.

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