The President may award a silver star of appropriate design, with ribbons and appurtenances, to a person who, while serving in any capacity with the Army, is cited for gallantry in action that does not warrant a medal of honor or distinguished-service cross—
((1)) while engaged in an action against an enemy of the United States;
((2)) while engaged in military operations involving conflict with an opposing foreign force; or
((3)) while serving with friendly foreign forces engaged in an armed conflict against an opposing armed force in which the United States is not a belligerent party.