Strategos

From Orson Scott Card Wiki

The strategos (plural strategoi; Greek στρατηγός) (literally meaning "army leader") was in charge of Solar System defense in the Bugger wars. Before the events of Ender's Game, all of the strategoi were Jewish; during the second invasion, a Israeli Jew was strategos. After the Third invasion Bean was given the title by Peter Wiggin the Hegemon.