NASSIB LAHOUD, Lebanon's most recent ambassador to Washington, is a quietly competent person. But when he saw the frequent use of the word "Lebanonization," meaning national disintegration, he would become visibly upset.He need not have worried. There is already a new paradigm for third-world breakdown. "Sudanization": the prolonged agony that befalls a former cold war bastion when it becomes irrelevant to the north. During the cold war, Sudan's rulers were told by Washington - and Moscow - that they were front-line players. The influx of military aid from superpowers skewed the politics of Sudan, and of many third-world states. Corrupt regimes were shored up, not because they met their people's needs, but to serve superpowers' interests. Then, 18 months ago, the cold war contest for global power abruptly ended. Moscow scaled back nearly all its third-world aid programs, except to Cuba and Afghanistan. (This cutback helped seal the recent collapse of the Marxist regime in Sudan's neighbor, Ethiopia.) Washington has cut back its aid to the third world, too. In a place like Sudan, there is now little long-term aid of any kind flowing in. But in the capital, Khartoum, one legacy of the cold war lives on: a military regime, which is continuing the eight-year-long campaign to impose Islamic law on all Sudanese. The southern one-third of the Sudanese aren't even Muslims. They have resisted the Islamic-law campaign. And the result of the Khartoum government's campaign? A civil war that has displaced three million southerners and cataclysmically disrupted food supplies. At one point in 1988, roughly one-fourth of the south's million Dinka people died of starvation. Time was, during Sudan's numerous earlier political crises, outside forces would intervene. Egypt's President Hosni Mubarak first came to international attention leading an Egyptian intervention in Khartoum in 1970. But now, when Sudan's crisis is deeper, no outsiders care. The US Committee for Refugees is predicting further mass starvation in 1992 if supplies are not moved in rapidly. Francis Deng, a former Sudanese cabinet member now at the Brookings Institution, remains cautiously hopeful. He judges the best plausible scenario would be a gradual stabilization of the present standoff. Both the northern Islamists and the southern secularists will continue to try to rule the whole country. But over time, each could become reconciled to administering its part. Then they could work out a new way to coexist - under a broad, regional umbrella. Sound familiar? Those outcomes are also being discussed in Yugoslavia. During this century, world trends tended to strengthen the role of central state authorities. Sovereignty was considered absolute. But that view no longer corresponds to reality. Policymakers need to think of sovereignty as comprised of numerous kinds of power: power to allocate natural resources, power to determine citizenship, power to impose laws, and power to raise armies. Some of those powers can be developed to communities within the existing states, and some pooled upward into multi-state groupings like the European Community. Those pragmatic visionaries who designed the US understood how power could be divided between Washington and the states. So why does the preference of our leaders seem focused - in Yugoslavia, in the Soviet Union, in Sudan - on preserving relations with central authorities? The Sudanese are not out of the horrors of civil war yet. Nor, most likely, are the Yugoslavs. In both countries, the policies pursued by the US over the past 40 years played a big part in strengthening the anti-democratic "central" authorities in both countries. So we owe it to the people there to try and help them resolve their conflicts. We need to focus on human needs and provide creative American ideas on building new forms of cooperation between communities. And Lebanon? There, we already have the beginning of inter-group reconciliation. One of the signs of that was that Ambassador Lahoud recently took his family back home. A sincere patriot, and a Maronite Christian who is married to a Muslim, Lahoud spent most of the past decade outside his country, as a contractor and then as a diplomat. Now, he says his priority is to work on national reconciliation, democratization, and building new kinds of links between Lebanon's communities. If that is the "Lebanonization" of the future, then other countries should welcome it.