The article addresses the question which consequences the war on terrorism has for the practice of and thinking about humanitarian intervention. The discussions about the legality and legitimacy of humanitarian intervention reached their peak after the NATO bombardments against the Federal Republic of Yugoslavia to protect the Albanians in Kosovo in 1999. The terrorist attacks of 9/11, which led to the war on terrorism, however, changed the focus of attention. The central question for international lawyers is no longer whether states may use force to protect human rights, but whether the use of force in anticipatory self-defence is allowed under international law in view of new security threats. After describing humanitarian intervention after the end of the Cold War, the impact of the war on terrorism on the protection of human rights is analysed. Although some authors think that the war on terrorism can coincide with the protection of human rights, the present author is more pessimistic. Subsequently the concept of the responsibility to protect is discussed. The author concludes that this concept is less revolutionary as some authors claim it to be. Most importantly, it does not provide a legal justification for the use of force to protect human rights without permission of the Security Council. The last section of the article therefore investigates whether the principle of necessity can serve as a potential legal justification for an intervention for human protection purposes without Security Council authorization.