War or Peace? - International Legal Issues concerning the Use of Force in the Russia-Ukraine Conflict

The Russian Federation launched an armed invasion of Ukraine on 24 February 2022, resulting in an international armed conflict of a level unprecedented since the Second World War. This article attempts to clarify the main international legal issues concerning the use of force and the support to of the belligerent parties. In the first part, it evaluates the Russian claims that the use of force is in accordance with the rules of international law, i.e. whether self-defence, the protection of nationals or humanitarian intervention could justify the intervention. In the second part, it investigates whether supporting one of the belligerent parties, especially Ukraine, could amount to a violation of the rules of neutrality or even constitute participation in the Russia–Ukraine conflict.