A s the guest editors of the Security and Defence Quarterly, we are delighted to present a Special Issue devoted to the use of proxy forces in modern warfare. This phenomenon, the outsourcing of war and employment of non-state actors on the battlefield, however ancient, has been gaining momentum recently as developments in almost all contemporary conflict zones illustrate. Raging from the Central African Republic, to Libya, Syria, Ukraine, and beyond, contemporary wars are being waged more and more with or through non-state actors -proxies. Whether foreign military interventions, counter-terrorism operations, training missions, or hybrid wars, proxies have been there and, seemingly, are to remain. Therefore, it fell upon us to ensure that such an urgent and pertinent topic should not evade deeper academic scrutiny and, together with our corresponding Authors, both practitioners and academics, we hope that this Special Issue at least partially achieves this.The idea of this special volume of the SDQ came after a conference organised by the George C. Marshall European Center for Security Studies in January 2020, where we both presented studies on proxies for countering terrorism in different regions of the globe. It was a very relevant event considering the developments in various parts of the world, and we learnt that the use of proxies by states has been a bigger phenomenon. Since then, we have had many discussions in person and over on-line platforms during https://securityandefence.pl/