The use of force is a continuing dilemma for UN peacekeeping missions and for the troop-contributing countries. How to use force while not becoming party to a conflict? This paper provides a chronological review of the UN’s operational experience in the use and non-use of force, showing the benefits and drawbacks of both. It highlights the period of crisis in the mid-1990s, when the UN could not summon the political will or the means to use the required force in the face of crises in Bosnia, Somalia and Rwanda. But, after absorbing these painful lessons, the United Nations showed in the new century it could use force in Sierra Leone, D.R. Congo, Haiti, and the Central African Republic. In all of the Africa cases, attack helicopters played a major role in robust peacekeeping. The helicopters not only provide mobility for rapid access, but also protection, close air support, a deterrent and a unique force multiplier. As such, they earn the designation of ‘key enabler’ - one that the United Nations is chronically short of and which warrants further provision and support from Member States. This paper provides insights into the diverse challenges, expectations and requirements for use of force. At the same time, it discusses the concerns caused by the shift to peace enforcement. This paradigm shift must be handled well if the United Nations is to move from a reactive to a pro-active approach and to make a long overdue shift from postconflict stabilization to the prevention of conflict.