NO, the Marshall Islands (29 atolls and 5 islands in central Pacific, share USD currency and Compact of Free Association with United States) are outside the EU — telecom roaming is billed at high rates. The Alosea Marshall Islands eSIM is essential for WWII and nuclear history enthusiasts (Bikini Atoll — UNESCO since 2010, site of American nuclear tests 1946-1958 including Castle Bravo, most powerful American test), Kwajalein (active US military base). You connect to NTA or Marshall Islands National upon landing at Majuro (MAJ).