Trade, not military might, could prove the real key to prosperity, power, and peace for modern nation-states, according to this speculative but credibly documented brief. As a former member of the State Department's Policy Planning Council, Rosecrance has few illusions about the planet's swords being beaten into ploughshares any time soon. In fact, he believes ""a tolerable balance"" in geopolitical power is necessary to sustain an international trading system. But since the end of WW II, he observes, the rewards of cooperative commerce have outweighed those of defense spending for a host of countries. Among other success stories, he cites Pacific Basin lands, including Japan (""a kind of Venice""), and West Germany (""a lineal descendant of the Hanseatic League""). On the other side of this coin, he points to so-called recalcitrants--the US, USSR, and militant Third World nations. Having focused on territorial objectives at the expense of global economic development, the two contentious superpowers are not faring as well as smaller (and less bellicose) rivals in trade competition, he concludes. Rosecrance puts his thesis into historical perspective, tracing the emergence of territorial (i.e., warfare) states during the 17th and 18th centuries. He attributes their subsequent durability to the preoccupation of diplomats as well as their governments with sovereignty and a reluctance to accept interdependence as being in their national interests. In the author's optimistic opinion, parochial principles of this sort are being rapidly overtaken by marketplace events. Conceding that nuclear-age realities will make the transition to a consistently peaceable trade-based kingdom here on earth a tricky proposition at best, he nonetheless characterizes most alternatives as unthinkable. A plausible scenario that artfully blends prophecy and pragmatism.