As viewed by Moscow, the U.S. Strategic Defense Initiative SDI represents a political, scientific-technical, and military challenge to the Soviet Union. The foremost Soviet strategic concern is that the United States will be able to develop a combined offensive-defensive posture that would not simply deny Moscow a preemptive counterforce option, but, more importantly, would provide die United States with unilateral options for employing nuclear weapons for political purposes. Strategic defenses, Soviet commentators argue, make particular sense for the United States in the context of that country’s efforts to develop limited nuclear options and to maintain a deterrence umbrella over its European and Asian allies. Coupled with the deployment of new theater-nuclear systems capable of reaching targets in the USSR, strategic defense is seen as offering the United States the prospect of fighting nuclear wars while escaping the consequences. An effective strategic U.S. defense would undercut the decades-long Soviet effort to create a strategic force posture capable of countervailing or paralyzing U.S. military power.