From Brest-Litovsk to Rome: Pacts That Built and Broke the Twentieth-Century Order

Signed on 3 March 1918, this separate peace took Soviet Russia out of the First World War at a heavy price: Russia gave up Ukraine, Finland, the Baltic lands and Poland, and a supplementary agreement added six billion gold marks in reparations. Germany's defeat in November 1918 voided it within months.

Signed on 10 September 1919 with the Republic of German-Austria, it carried the Covenant of the League of Nations into the peace settlement, so the United States did not ratify it and made a separate peace with Austria in 1921.

Negotiated at the Washington Naval Conference of 1921 and 1922, it tried to prevent a naval arms race among Britain, the United States, France, Italy and Japan by limiting battleships, battlecruisers and aircraft carriers, while leaving cruisers and destroyers largely unlimited.

Seven agreements negotiated in late 1925 guaranteed the borders between Germany and France and Belgium and the demilitarized Rhineland, yet gave Germany's eastern border no guarantee, which left open the chance of later revision.

In 1928 the signatory states renounced war as an instrument of national policy. The pact had no enforcement mechanism and did not stop the aggressions that followed, but it later supplied part of the legal basis for prosecuting wars of aggression at Nuremberg.

Concluded between Nazi Germany and Japan on 25 November 1936 and aimed at the Communist International, it was joined by Italy in 1937 and by Spain and Hungary in 1939, and marked the start of the Axis alignment.

Signed in Berlin on 27 September 1940 by Germany, Italy and Japan, it was a defensive military alliance. Yugoslavia's accession provoked a coup in Belgrade two days later and an invasion of that country by Germany, Italy and Hungary.

The 1944 agreement set the monetary rules for 44 countries, tying currencies to the United States dollar and the dollar to gold, and created the International Monetary Fund. The system lasted until the Jamaica Accords of 1976.

At Yalta in February 1945 Roosevelt, Churchill and Stalin agreed on occupation zones for Germany, on moving Poland's borders westward along the Curzon Line, and on the structure of a new United Nations organization.

Signed in San Francisco on 26 June 1945 and in force from 24 October 1945, it created the six principal organs of the United Nations and set the principle of sovereign equality and the prohibition on using force against another state's territorial integrity.

Issued on 26 July 1945, it called on Japan to surrender unconditionally, limited Japanese sovereignty to the home islands, and promised eventual establishment of a peacefully inclined government. The Soviet Union endorsed it only after declaring war on Japan.

Signed in Washington on 4 April 1949 by twelve states, its Article 5 treats an armed attack on one party as an attack on all. It created a peacetime military alliance without precedent for the United States.

Signed on 25 March 1957 by Belgium, France, Italy, Luxembourg, the Netherlands and West Germany, it established the European Economic Community and a common market, the ancestor of today's European Union.