WASHINGTON — ALL over the world the cohesion of nation-states is under attack from within. In the Soviet Union, Mikhail Gorbachev seems more harried every day as republic after republic demands autonomy. In Yugoslavia, long an uneasy alliance, Croats, Serbs, and Slovenes are teaching a new generation the meaning of the word ``Balkanization.'' Kurds fight for their own piece of the Middle East, while Muslims and Christians riot in Nigeria, and even Canada faces a separatist threat, from Quebec.
At the same time, national sovereignty is being challenged by powerful outside forces. The world economy increasingly knows no borders, while satellite transmissions leap barriers to information flow. Western national security is based on coalitions, and the supranational European Commission has become a prize club with a waiting list of applicants.
Is the nation-state doomed? Not likely. It's a durable, albeit modern, political institution. But with the end of the cold war the concept of the nation-state is facing unprecedented stress. It's being challenged by forces both internal and external - what historian John Lewis Gaddis calls ``the forces of fragmentation and integration.''
The clash between these trends could become just as pervasive and intense as was the contest between democracy and communism. Such a world might well represent a return to the more complex geopolitics that existed before the freezing effect of the cold war.
``The cold war is something we're going to increasingly see as an artificial period of history,'' says Dr. Gaddis, a professor of history at Ohio University. Nation-states, meaning governments formed around a ``nation'' of a unified people, are not a long-standing way of dividing up the globe.
The concept of nation-statehood that is familiar today was born in the American and French Revolutions of the late 18th century. It wasn't until the late 19th century that scholarly dictionaries defined ``nation'' as anything more than an ethnic group, points out University of London history Prof. Eric Hobsbawm.
``In its modern and basically political sense the concept `nation' is historically very young,'' writes Dr. Hobsbawm in his new book, ``Nations and Nationalism since 1780.''
More than 90 of the 159 member nations of the United Nations General Assembly have come into existence only since World War II. Many of these are artificial creations, carved out of the remnants of empires by big-power diplomats, with more regard for relations between the major nations than for natural national divisions.
Today's squabbles around the world can often be traced to this approach to nation-building. Thus Eritrea, which developed a regional identify as an Italian colony, was grafted onto Ethiopia, from which it has been fighting to escape ever since. The Kurds, promised their own state by the victorious allies of World War I, found themselves part of Iraq, instead - with results lately visible to all.
That fragmentary forces are loose in the world, with peoples who feel trapped in another nation trying to get out, is obvious from a glance at international headlines. The Irish Republican Army plants a bomb in Belfast; in India, Kashmiri rebels trade fire with government troops; Mozambique rebels postpone peace talks; Quebec continues to threaten to leave Canada.
Hobsbawm judges that many modern nationalist movements are ``essentially negative,'' insisting on ethnic, linguistic, or religious purity. ``They seem to be reactions of weakness and fear, attempts to erect barricades to keep at bay the forces of the modern world,'' he writes.
The erosion of Soviet power has unfrozen dozens of nationalistic conflicts. Yugoslavia may well split up, with dire consequences for European stability, over ethnic disputes that Western publics find mystifying.
``In Eastern Europe, nations are now not wanting to integrate, but to create their own little states. In Western Europe, the trend is toward integration, away from the nation state,'' says F. Stephen Larrabee, a Rand Corporation Sovietologist.
There's the irony. Among developed nations the integrating forces of modernity are increasingly transcending old barriers of technology, culture, and politics.
That the world economy is being internationalized through increases in world trade and the spread of multinational corporations is a truism. The easy flow of capital across borders is eating away at the ability of governments to exercise control over their own interest rates and fiscal policy.
``Interdependence has cut into sovereignty. That's not a fact governments can make a choice about,'' says Stanley Sloan, Congressional Research Service international security policy specialist.
Economics may be the primary world integrating force, but it's far from the only one. The communications revolution spawned by satellite transponders and the microchip, which helps make instant capital flows possible, also contributes to an integration of ideas, says Gaddis. Chinese students constructed a model of the Statue of Liberty; Czech president Vaclev Havel talks to the United States Congress about Jeffersonian democracy. Supranational organizations, long a favorite of idealists, also seem to be moving toward real integrative power. The EC is the primary example, but the UN may be now revitalized as well.
It is not a given that integration is better than fragmentation. The unchecked flow of money and people across borders might not make the world a safer place, cautions Gaddis.
``The end of the cold war ... brings not an end to threats, but rather a diffusion of them,'' he says.