The latest issue of the Journal of Strategic Studies addresses the issue of UN peacekeeping and the use of force, considering how far this is removed from the UN’s original peacekeeping principles of consent, impartiality and the use of force only in self-defence. There is free access to the introductory article: Berdal, M. and Ucko, D. (2014) ‘The United Nations and the Use of Force: Between Promise and Peril’, Journal of Strategic Studies, 37(5): 665-673, DOI: 10.1080/01402390.2014.937803, which is accessible here or via: http://dx.doi.org/10.1080/01402390.2014.937803
Other articles are accessible via UoL’s online library (you will need to use your username and password): http://www.tandfonline.com/doi/full/10.1080/01402390.2014.937803#.VGSHuf1yaUk