 Two years later during the Russo-Japanese War, the belligerents agreed to exchange lists of prisoners, communicating through France as the protecting power for Russia, and the United States as the protecting power for Japan.The practice of swapping prisoner lists became customary and was eventually included in the Geneva Convention of 1929.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.