un arms embargoes have been increasingly applied to civil wars, yet these embargoes have tended to be either irrelevant or malevolent in their effects. arms embargoes are rarely enforced in a civil war; they undermine the credibility of the un; they are unlikely to change the political positions of civil war participants; they criminalise target societies; and they benefit arms suppliers willing to break the rules. this article argues for the reform of partial arms embargoes, which target select groups in a civil war. it also argues for the restriction in use of impartial embargoes, which apply to all sides in a civil war. enforcing impartial embargoes can actually make the situation worse, by shaping the course of the civil war in unpredictable and immoral ways.