This pamphlet, DA Pam 11-31, describes how the Army supports achievement of geographic combatant command (GCC) and functional combatant command (FCC) campaign plan intermediate military objectives and strategic end states through security cooperation (SC) activities conducted by, with, or through theater Armies or functional Army service component commands (ASCCs). This pamphlet reviews Army SC roles and responsibilities; presents planning, resourcing, execution, and assessment methodologies for consideration; and provides other factual information important to Army SC planners.