Frequently characterized as either mercenaries in modern guise or the market’s response to security gaps, private military companies...play an increasingly important role in armed conflicts, UN peace operations, and providing security in unstable states...their growing significance raises fundamental questions about their nature, their role in different regions and contexts, and their regulation...[There is] tension between efforts at regulation and market forces. Acceptance of that market will largely depend on the reality and the perception of accountability mechanisms to guard against abuse....Concerns relate primarily to the use of potentially lethal force by PMC personnel... [refers to Executive Outcomes, Military Professional Resources Incorporated (MPRI) (part of L-3 Communications), Sandline International]