ImagesMilitary History Operation Flintlock February 1, 2011June 2, 2017 Chris Carter Marines on Roi-Namur. Source: Flickr On January 31 and February1, 1944, Marines and soldiers stormed the Japanese-held beaches of Kwajelein and Roi-Namur in the Marshall Islands. In a few short days, the force would overwhelm the defenders and gain control of the Marshall Islands. Related Content