yes / The 1990s witnessed a change in the way wars were fought as the amount of available weaponry increased and the types of actors engaged in warfare multiplied. The opening up of the international arms trade, in particular with new buyers and more channels of supply, has raised concerns about who purchases weapons and for what use. Afeature of this changing nature of conflict has been the continuing, if not growing, presence of mercenaries and the emergence of private companies contracted to provide military and security services. These range from logistical support and training to advice and procurement of arms and on-the-ground intervention. This briefing highlights how the activities of mercenaries and private military and security companies can contribute to small arms proliferation and misuse and examines steps the international community can take at the UN Small Arms Conference and elsewhere to effectively combat mercenarism and regulate the activities of private military and security companies. The role played by these companies relates not only to provisions contained in the contracts they sign with their clients to provide large amounts of weaponry, but also how the military and security services and training that they provide contributes to the demand for weapons in the regions where they operate. There are a number of ways in which mercenaries and private military and security companies are involved in small arms proliferation. These include: l Arms brokering and transportation activities l Violations of UN arms embargoes l Impact on human rights and humanitarian law l Driving demand for small arms Various measures already exist to ban the activities of mercenaries and regulate some of the activities of private military and security companies either through national legislation or international agreements. However, there is concern these efforts are neither comprehensive nor accepted widely enough to effectively control the activities of mercenaries and private military and security companies.