History of French foreign relations of construction materials (especially concrete), tanks (because of lack of road access and difficulty in the jungle terrain), and air cover precluded an effective defense, culminating in a decisive French defeat at the Battle of Dien Bien Phu. At the international Geneva Conference on July 21, 1954 the new socialist French government and the Việt Minh made an agreement that was denounced by the government of Vietnam and by the United States, but which effectively gave the Communists control of North Vietnam above the 17th parallel. South Vietnam, with heavy American support. continued under Emperor Bảo Đại. In 1955 Bảo
49th parallel north the 1846 Oregon Treaty. This agreement divided the Oregon Country between British North America and the United States by extending the 49th parallel boundary to the west coast, ending in the Strait of Georgia; it then circumvents Vancouver Island through Boundary Pass, Haro Strait, and the Strait of Juan de Fuca. This had the side effect of isolating Point Roberts, Washington. Although parts of Vancouver Island and parts of Eastern Canada are south of the 49th parallel, and parts of the United States (Alaska, Northwest Angle) are north of it, the term "49th parallel" is sometimes used metonymically to refer