By early 1944, the United States Marine Corps had already made significant strides in their campaign to reclaim territories lost to Japanese forces during World War II. Following pivotal victories in the Southwest Pacific—beginning with Guadalcanal in August 1942 and continuing at Tarawa in November 1943—American forces were poised to take the next crucial step assaulting the islands held by Japan prior to 1941. These strategically important islands, mandated to the Japanese by the League of Nations after World War I, were shrouded in mystery and speculation. With outsiders barred and illegal fortifications suspected, any push toward Japans inner defense ring had to navigate these uncertainties. The Marshall Islands emerged as the primary target, a geographic key identified by Marine planners as far back as 1921. - Summary by John C. Chapin