Two American debates on foreign policy and national security. The Reagan administration and those who share its ideology see today's Soviet Union as not much different from yesterday's, and yesterday's Soviet Union as not much different from Nazi Germany. Like its progenitors in the 1930s, the modern Soviet Union is a "totalitarian" state, and therefore by nature expansionist, armed to the teeth, disposed to violence, fond of diplomatic tests of political will, and - as a consequence of all these factors - hard to deter and harder to beat. A different view prevails among most of the arms control community, the NATO allies, and some American academics. In its foreign policy, the Soviet Union is seen as a fairly typical great power whose behavior in international politics can be explained by the mixture of fear, greed, and stupidity that has characterized most great powers in the past as they have tried to secure their borders and pursue their interests in a world without law. It does not like to take great risks, it fears war, and it is, at worst, opportunistically expansionist. In sharp contrast to Nazi Germany, the Soviet Union is more conservative than reckless; if anything, nuclear weaons have reinforced this conservatism.