This study aims to illuminate the concept of «proxy war», as well as its signs and modification in the XXI century. The paper highlights the advantages and disadvantages of this type of war. The focus is on the analysis of the Syrian conflict. The main participants of the civil war in Syria, their interests and motives for involvement in the conflict, in particular, the main "third-party" players - Russia and the USA- are examined. An analysis was made of the impact of external actors on the domestic political situation in Syria. The forms of participation of "outside" forces and the ways of their support of the warring parties are described. As a result of the analysis, it was revealed that the Syrian conflict is a proxy war and has all the signs of this type of war. The reasons for the protracted nature of the civil war in the Syrian Arab Republic are identified.