From the start of World War II, the Navy was involved in a number of operations, participating in the Battle of the Atlantic, the Norwegian Campaign, the Dunkirk evacuation and, briefly, the Battle of the Mediterranean. However, after the fall of France in June 1940, the Navy was obligated to remain neutral under the terms of the armistice that created the truncated state of Vichy France. Worldwide, some 100 naval vessels and their crews heeded General Charles de Gaulle's call to join forces with the British, but the bulk of the fleet, including all its capital ships, transferred loyalty to Vichy. Concerned that the German Navy might somehow gain control of the ships, the British mounted an attack on Mers-el-Kébir, the Algerian city where many of them were harbored. The incident poisoned Anglo-French relations, leading to Vichy reprisals and a full-scale naval battle at Casablanca in 1942 when the Allies invaded French North Africa. But the confrontations were set aside once the Germans occupied Vichy France. The capital ships were a primary goal of the occupation, but before they could be seized they were scuttled by their own crews. A few small ships and submarines managed to escape in time, and these joined de Gaulle's Free French Naval Forces, an arm of Free France that fought as an adjunct of the Royal Navy until the end of the war. In the Pacific theatre as well, Free French vessels operated until the Japanese capitulation; was present at the Japanese Instrument of Surrender.