The purpose of this analysis is to evaluate the effectiveness of -fly zones and to assess the contextual factors that influence success. The measures of success for the -fly zones are: a) achievement of air objectives b) congruency between air objectives and higher level objectives, and c) actual effects of each -fly zone on higher level objectives and a desired end state. The air objectives of each -fly zone has been to prevent flights of all aircraft t in support of the allied forces, to protect civilians from aerial bombardment, and to provide air supremacy for other missions. The -fly zone over Bosnia-Herzegovina achieved limited success in achieving air objectives, while the two -fly zones over Iraq have been very successful. The air objectives of each -fly zone have been congruent with national objectives. The success of the November 1995 negotiations in Dayton, Ohio is testament to the positive progress toward all of the long term objectives for Bosnia-Herzegovina. The long term effects of operations in Iraq are unclear. To overcome limitations imposed by the physical environment, proper synchronization between all forces will be essential. Rules of engagement for military operations should simplify coordination, integration, and identification among forces so that execution can be decentralized. The long term impact of U.S. military presence in the Gulf should be studied further. If ending the oppression of the Shiites in southern Iraq is a U.S. objective, then a reevaluation of the forces in theater is necessary. This study supports the hypothesis that -fly zones are an effective strategy for U.S. forces.