The United States was initially a popular choice for protecting power, going back to its protection of the North German Confederation during the Franco-Prussian War. The pinnacle of American diplomatic protection came during World War I, when the United States accepted reciprocal mandates from five of the largest belligerents on both sides: Britain, France, Austria-Hungary, Germany, and the Ottoman Empire. Between 1914 and 1917, the United States accepted a total of 54 mandates as protecting power. When the United States entered the war on the Allied side in 1917, the American mandates were transferred to smaller neutrals, with the Netherlands, Spain, and Switzerland being popular choices.