This was the US occupation of French Guiana in South America and the islands of Martinique and Guadeloupe in the French West Indies by forces of the US Army (30 June 1943).
On 12 December 1941 President Franklin D. Roosevelt’s emissary, Rear Admiral Frederick J. Horne, met Vice-amiral Georges Robert, the Vichy French high commissioner for the Antilles (Martinique and Guadeloupe), Guiana and, off the east coast of Canada, the tiny islands of St Pierre et Miquelon, to discuss terms for military neutralisation of French possessions in the western hemisphere.
Matters rested there until March 1943, when there were Free French demonstrations in Cayenne, the colony’s capital. The city’s mayor telegraphed Général de Brigade Charles de Gaulle, the Free French leader, to inform him of colony’s rally to the Free French cause and to request the appointment of a new governor. On the advice of the US consul, who was acting to prevent the ascendency of de Gaulle and thus secure basing and other rights in Guiana, the mayor sent a similar telegram to Général d’Armée Henri Giraud, the other primary leader of the French opposed to Vichy France.
Robert still refused to resign, and on 30 April the USA broke off diplomatic relations with his administration. It was only on 30 June that the pressure of local resistance groups finally persuaded Robert to resign in favour of the Giraudist governor appointee, who had reached Cayenne before the Gaullist contender as the latter had not been able to find transport. The new administration soon reached agreement with the Americans, who thus secured the advantages they had sought.