Prior to July 1954 the expanse of mainland Southeast Asia now occupied by South Vietnam, North Vietnam, Laos, and Cambodia belonged to France. Together these possessions constituted French-Indochina over which the French had exercised political control in one form or another, with one exception, since the last quarter of the 19th century. The only interruption occurred following the capitulation of France in June 1940. Exploiting the disrupted power balance in Europe, and attracted by the natural resources and strategic value of the area, Japan moved into northern French-Indochina less than four months after France had fallen. In 1941 the Vichy French government agreed to Japanese occupation of southern French-Indochina. Soon Japanese forces controlled every airfield and major port in Indochina. Under this arrangement the Japanese permitted French colonial authorities to maintain their administrative responsibilities. But as the tide of war began to turn against the Japanese, the French became increasingly defiant. The Japanese terminated this relationship on 9 March 1945 when, without warning, they arrested colonial officials throughout Indochina and brutally seized control of all governmental functions. Six months after the dissolution of the French colonial apparatus in Indochina, World War II ended. The grip which Japan had held on most of Southeast Asia for nearly half a decade was broken on 2 September 1945 when her foreign minister signed the instrument of unconditional surrender on board the battleship USS _Missouri_. Shortly thereafter, in accordance with a previously reached Allied agreement, Chinese Nationalist forces moved into Tonkin and northern Annam to accept the surrender of Japanese forces. South of the 16th parallel, British units arrived from India to disarm the defeated Japanese. A detachment of 150 men from a small French Expeditionary Corps arrived by air in Saigon on the 12th to assist the British, who had included them only as a courtesy since France was not among the powers slated to receive the surrender of the Japanese in Indochina. But the end of World War II and the arrival of Allied forces did not end the struggle for control of French-Indochina. Instead, it signalled the beginning of a new conflict in which the contestants were, in many respects, more formidable. One of these, the French, moved quickly to restore their former presence in Cochinchina and Annam. Reinforced with additional units, they occupied most major towns between the Mekong Delta and the 16th parallel by the end of 1945. Two months later French negotiators secured an agreement with the Chinese Nationalists whereby French units would replace the Chinese occupation forces north of the 16th parallel. [Illustration: MAJOR CITIES OF SOUTH VIETNAM ]