Earthwar was an influential storyline published in issues #241-245 of Superboy and the Legion of Super-Heroes (July-November 1978). It is notable as arguably the most ambitious of all storylines of the Legion up until that point. Besides encompassing five issues (including the Prologue in #241), it had a complex plot with several layers of opponents for the Legionnaries, most of them major or at least recurrent foes, and considerable elements of political and military intrigue.
Earthwar was one of the very last storylines happening during Wildfire's term as leader. The writer was Paul Levitz. James Sherman was the penciller for the first two issues, then apparently walked out after disagreeing with the decision on having a magic-using wizard (Mordru) be the final villain behind all the high-tech science fiction factions he had been hoping for. He was replaced by Joe Staton.