War and hunger - a deadly duo. Ongoing famine in four nations linked to civil strife. IN AFRICA, GUNS INSTEAD OF BUTTER

War, not drought, has become the main cause of hunger in the four African nations with the most people facing starvation. Ethiopia, where more than 1 million people are cut off from food relief by an escalating war, is a prime example, according to United States and United Nations officials. In Sudan, Mozambique, and Angola, several million more people are also cut off from emergency food supplies because of war, officials say.

``In the past, the impact of natural disasters - drought, flood, pestilence, and disease - was the prime factor, the momentum, behind the emergency needs,'' says Charles Gladson, the top Africa official for the US Agency for International Development (AID). Today, the main cause for hunger in these four nations is war, he recently told US congressional panels.

Sufficient donations of food have poured in from around the world. But increasingly, war makes it impossible to get food to the people.

War causes hunger in Africa in various ways:

Rebels attack and shoot down truck and airplane convoys of food relief. Truck convoys are often delayed while mined roads are cleared and by roadblock checks that, under wartime conditions, are especially tedious. In some countries, governments require military escorts for convoys, but these are available only sporadically for relief convoys. (In Ethiopia, outside relief agencies refuse military escorts to try to avoid rebel attacks.) And governments usually do not allow food shipments to rebel territory.

Civilians in conflict zones flee homes and farms in search of food and safety from rebel attacks - and sometimes from marauding soldiers. Farmlands go unplanted. The decrease in crop production, added to the increase of the urban populations and the number of people displaced in rural areas, makes these nations increasingly dependent on food aid and food imports. Payment for food imports further drains the nations' scarce foreign exchange, which might otherwise go into farming equipment, seed, and fertilizer.

``It's a vicious circle,'' says a senior UN official.

In addition, it is especially difficult to provide people on the move with regular food relief. Some die of hunger on long treks to refugee camps in neighboring countries or to towns and cities in their own country. In the worst case, people congregate in huge makeshift feeding camps, where they are especially vulnerable to disease because of crowded, unsanitary conditions.

Governments distort priorities. Money goes to the war which could reduce hunger if spent on agriculture extension services, education, and health programs.

Ethiopia

After a spate of significant battle losses to the rebels, the government this month began a military build up in Tigre and Eritrea, the two provinces hardest hit by drought and hunger. And it ousted from those regions all relief agency workers, except for a few from the UN.

Up to that point, relief officials had been meeting the food demands of some 6 to 7 million people in areas hit by drought. Now, about 1 to 1.5 million are completely cut off from food deliveries, says Patrick Johns, director in Ethiopia of Catholic Relief Services.

Relief officials had also managed to avert the formation of large feeding camps by widespread dispersal of food relief to small government-held towns throughout the provinces. Some of these towns have become battlegrounds, and food distribution there and elsewhere has been halted. People will soon be on the move.

All of these developments have come at a time when farmers should be preparing to plant their next crop. According to a number of relief agencies, the Ethiopian government has not made needed improvements - recognized during the 1984-85 famine - on roads and ports used for both general and emergency food relief. And farmers are not getting enough seeds, tools, or fertilizers.

Sudan

Southern Sudan's war has driven nearly 2 million people from their homes, according to UNICEF. More than 1.5 million are internally displaced, many of them having fled from insecurity and hunger in the south to northern cities where there food and public services are already scarce. About 250,000 fled to other countries.

Commercial and relief shipments of food and other necessities have been off and on for the last two years. Relief officials and Western governments have accused the Sudanese government and the rebels of using food as a weapon: halting relief food shipments to civilians and commandeering food shipments for fighting forces.

A severe drought in various regions, combined with rampant destruction and disruption of agriculture in the south, has left Sudan seriously short of food supplies, according to AID reports. Sudan, which already has a staggering foreign debt, is spending about $400,000 a day on the war, according to US government estimates. This financial drain has led the government to halt a number of development projects, AID officials say.

Mozambique

The Mozambican government, which has been fighting an insurgency for 12 years, is so strapped for money that its own Army is underfed and barefoot.

The war has cut more than one-third of the population of 14.5 million off from their normal food supply in rural and urban areas. The rebels have declared it their intent to bring the government down by destroying the nation's economy. They have attacked food relief convoys and so terrorized rural civilians that about 3.3 million have fled homes and farms, either to the cities or to other countries, according to a UNICEF report.

Every day more people ``literally naked and starving - stagger into relief centers in Mozambique,'' says Mr. Gladson. And 50 to 60 percent of the nation's children are suffering from malnutrition, according to UNICEF.

Although the nation is potentially rich with minerals, petroleum, and natural gas deposits, virtually none of these have been tapped. The little money that the Mozambican government puts in to agriculture, combined with large amounts of funding from Western development agencies for both agriculture and transport, is increasingly seen as useless. Transport routes are unsafe and too many farmers have fled their land. Crop production overall has plunged. And what crops are planted are often destroyed by the rebels.

Angola

This nation has one of the world's highest infant mortality rates, a fact that UNICEF links directly to food shortages and destabilization caused by the war. Rebel activity is most intense in Angola's central highlands, which traditionally grew most of the country's maize.

Although Angola's weather has been good for growing crops, production is declining overall because of ``civil strife,'' according to the latest report by the UN Food and Agriculture Organization.

Since independence in 1975, some 3.5 million civilians - about 40 percent of the current population - have fled war-torn rural areas for the towns and cities. Farmers have quit farming altogether or become subsistence farmers. The overall trend is causing ``serious food shortages'' in urban areas, according to the latest world survey by the US Committee for Refugees.

According to a 1987 report by Tony Hodges of the Economist Intelligence Unit in London, 53 percent of Angola's total imports in 1985 - based on preliminary national figures - was military imports.