Missile defense has become an area of controversy in the US-China relationship. The US government sees an enduring role for a range of relatively limited missile intercept capabilities, designed to protect the US homeland, deployed forces, as well as allies and partners by: 1) dissuading other countries from acquiring and deploying ballistic missiles by reducing their perceived value; 2) deterring the use of ballistic missiles by introducing the possibility of operational failure; and 3) defeating a missile attack. China, by contrast, questions US motives in developing such a system and is particularly concerned with the potential evolution of the technology.