Complex sentence: On January 1944 Maghakian volunteered to participate in another assault, that of one against Kwajalein Atoll of the Marshall Islands in what would be called the Battle of Kwajalein.
Split into simpler sentences: On January 1944 Maghakian volunteered to participate in another assault mission. The assault would be on Kwajalein Atoll of the Marshall Islands in what would be known as the Battle of Kwajalein.