During the interwar period U.S. forces were involved in several minor actions, including the Russian Civil War and multiple events in the Caribbean that have since become known as the Banana Wars; also, the Yangtze Patrol was directly and indirectly affected by the Second Sino-Japanese War and other events. Between 1918 and 1933, at least 3,900 Filipino Americans served in the U.S. Navy at any given time as mess stewards, having largely replaced African Americans in that rating. Up to World War I, Filipino sailors were able to serve in a range of occupations in the U.S. Navy; however, after World War I, a rule restricted Filipinos to the ratings of officer's steward and mess attendant. These restrictions did not extend to the Insular Force, which was limited to 500 individuals from Guam or the Philippines.