G.I. Combat is a long-running comic book

War comics

War comics is a genre of comic books that gained popularity in English-speaking countries following World War II.-American war comics:Shortly after the birth of the modern comic book in the mid- to late 1930s, comics publishers began including stories of wartime adventures in the multi-genre...

 series published first by Quality Comics

Quality Comics

Quality Comics was an American comic book publishing company that operated from 1939 to 1956 and was an influential creative force in what historians and fans call the Golden Age of comic books....

 and later by National Periodical Publications, which was the primary company of those that evolved to become DC Comics

DC Comics

DC Comics, Inc. is one of the largest and most successful companies operating in the market for American comic books and related media. It is the publishing unit of DC Entertainment a company of Warner Bros. Entertainment, which itself is owned by Time Warner...

.
The focus of the book was on stories about American soldiers or G.I.s. Initially, the stories involved Cold War

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 adventures with strong anti-communist themes, but over time the focus shifted to tales from World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, and most of the stories from the mid 1950s on were set during this period.