Marshall Islands is another bunch of atolls and islands in Oceania. Their languages are English and Marshallese.
The islands were once a Spanish colony, until they sold it to Germany. In the World War I, they lost it, like their other colonies, to the Japanese. After World War II, their administration passed to United States, where they decided to make a few nuclear tests (actually, they even destroyed some atolls with the explosions nukes are dangerous). The country declared independence in 1979.
Probably the most famous landmark of Marshall Islands is the Bikini Atoll (the type of swimwear was named after it, not the other way around) and its bottom, where SpongeBob SquarePants and company reside. Actually, considering the nuclear tests in the area, the sheer weirdness of Bikini Bottom should be a surprise to nobody.
Also culturally notable is the Castle Bravo nuclear test conducted in 1954. Aside from being the first Hydrogen Bomb detonated, the test plays heavily into the Godzilla mythos, in the Big Guy's Origin Story. Rising Storm, interestingly, unlike most other World War II games set in the Pacific, actually bothers to cover the Battle of Kwajalein between the US 7th Infantry Division and the Imperial Japanese Army.
The Marshallese flag