Missile Technology Control Regime (MTCR) is the first international mechanism controlling proliferation of missiles and related technology. The core limitation imposed by MTCR is on proliferation of high propulsion ballistic missiles and related technology. It strictly limits the export of missiles capable of delivering a 500 kilogram payload to a 300-kilometer distance, otherwise known as 500kg/300km standard. MTCR also sets clear rules regarding the export behaviour of its member countries. The export limits guiding interaction among non-member countries apply equally to MTCR members. However, little attention has been paid to whether or not MTCR members indeed abide by MTCR rules.Taking into consideration the fact that missile defense uses the same technology as offensive missiles, this work is dedicated to understanding whether joint missile defense development programs between the United States and her allies might undermine the principles and rules of MTCR and therefore potentially contribute to the proliferation of ballistic missiles and related technology.