Eritrean nationalists, now in their 17th year of fighting for independence from Ethiopia are amused and embittered by the West's sudden interest in what has long been Africa's forgotten war.

Recent American and British denunciations of possible Cuban and Soviet military intervention in Eritrea on the side of Ethiopian government forces have not sparked any illusions among the nationalists about the chances of the West coming to their aid.

Their long struggle has taught them that Eritrean Nationalists have no strong friends - only changing and powerful enemies.

Their attitude is illustrated by their own cautious reading of the present Cuban role in Eritrea, where White House officials last week charged the Cubans were already actively involved in the fighting.

"We have no hard facts that the Cubans are involved in any front-line combat role," said a spokesman for the Eritrean Liberation Front. His counterpart in the Marxist-oriented Eritrean Peoples Liberation Front said: "The Cubans are not yet fighting, according to our information, but they are not in (the capital of) Asmara to play football."

"The whole world is against Eritrea," the EPLF spokesman added, "but let the Cubans and Russians come and fight for Eritrea for it will be their Vietnam."

Such pronouncements are not just bravado.They reflect a healthy suspicion of superpower behavior befitting a people numbering no more than three million men women and children who feel they have been cheated out of their legitimate national rights by foreign connivence.

Eritrean nationalists long ago realized that their fight to create a new nation with 600 miles of strategic coastline along the narrow entrance of the Red Sea inevitably would become caught up in superpower politics.

But Eritreans concede that this latest betrayal, by Cuba and the Soviet Union, really hurts. Many of the Eritrean nationalists consider themselves Marxists. Eritrean guerrillas were trained in Cuba in 1969 and 1970.

Also high on the Eritreans' black list are Britan and the United States. Britain is blamed for having maneuvered Eritrea into a federation with Ethopia in 1952 at the end of a United Nations mandate over the former Italian colony.

The United States not only is held guility in Eritrean eyes of having favored federation, but also of having gone along with the outright Ethiopian annexation 10 years later.

The prize for the United States was Kagnew Station, a highly sophisticated communications based in Asmara which only in recent years became obsolete.

Nor have the Eritreans and had happier experiences with fellow Africans.

Despite nearly two decades of efforts, the Eritreans have failed to persuade Black Africans that they have a case.

They argue that Eritrea is still a United Nations responsibility since it was brought about by a United Nations vote. They also argue that Ethiopia - in annexing Eritrea - betrayed its United Nation mandate.

The Black Africans simply do not want to know the details. Many are suspicious of the aid that Syrian, Iraq, Saudi, Arabia, Sudan and other Arabs have provided the Eritreans.

Almost all Africa fear that backing Eritrean claims to independence would throw open to challenge their own vulnerable and often arbitrary frontiers inherited from now departed colonial masters.

Even the Sudan, whose president Gaafer Nimeri once called for Eritrean independence, by mid-1977 was pushing a more prudent scheme for autonomy.

Sudanese efforts to mediate between the Eritreans and Ethopians have failed so far to bear fruit amid suspicions that the Soviets oppose any rapprochement. The Eritrean leaders demand total independence, contending that to ask anything less now would be political suicide. The Ethopians still profess to offer regional autonomy, but analysts here are convinced that Col. Mengistu Haile Mariam's military regime would prefer to crush the Eritreans if it can enlist Soviet and Cuban support for such a major undertaking.

At this point, Sudanese and foreign analysts here are working on the assumption that the Cubans and Soviets will intervene. A mid-March editorial in Pravda provided the ideological and political underpining.

Analysts are convinced, however, that military intervention could well pose a serious problem for the Kremlin Given the guerrillas a knowledge of the terrain, much of which is mountainous and ill-suited for armor, any plan designed to crush the nationalists who now occupy some 90 percent of the territory would have to be a brutal and destructive undertaking.

Such is believed to be the keenest desire of Col. Mengistu, who has just returned from a visit to Moscow.

But the Soviets could well prefer a less extensive operation involving opening up the road from the Red Sea port of Massawa to Asmara, and possibly south to the border of Ethiopia proper.

Even that limited an operation could prove difficult. On the road from Massawa to Asmara alone, there are more than 50 miles of mountains where the guerrillas are well enconsed.

Moreover, opening up that road would be of more political than military importance.

The guerrillas never managed to shout down traffic from Assab, the other Eritrean Red Sea port, and now the railroad from Djibouti to Addis Ababa is no longer cut by the Somalis.

But although the Ethiopians and their foreign backers are credited with being able to recapture most, if not all, the major towns and cities now under Eritrean guerrilla control, some analysts believe Soviet interests would be best served by a stalemate.

A minor victory or series of victories would still leave Ethiopia dependent on continued Soviet aid and allow Moscow's influence to grow.

The Soviets are also believed to still be intrigued by a plan to federate Eritrea, Ethiopia and Somalia. This scheme to further Soviet influence was first unveiled in the spring of 1976 by Cuban Prime Minister Fidel Castro during a visit to the Horn of Africa.

Military analysts also wonder about the timing of any anti-guerrilla offensive. The rainy season in much of Eritria begins in late May and continues until late October.

Some specialists feel the Soviets were surprised at the rapid success of their campaign to expel Somali forces from the Ogaden, and still need considerable time to work out plans for Eritrea.

A mid-March Ethiopian effort to push South from Asmara was stopped by the guerrillas, who claimed they killed as many as 1,500 Ethiopians, destroying six tanks and damaging three others.

Some analysts believe the Russians used the operation as a yardstick to judge how many Cuban troops might be required for an Eritrean campaign.

Reports on the number of Cubans in Asmara vary. The White House says between 200 and 300, the EPLF said more than a month ago that 2,000 were there, and a high Sudanese official suggests that "more than a thousand" were airlifted in over the past three weeks.

Some intelligence sources maintain that Cubans are now flying reconnaissance flights from Asmara. Ethiopian bombing of Eritrean positions has also become so much accurate that some sources wonder if the pilots are Ethiopian.

But the number already in action is less important than the knowledge that there are, according to U.S. estimates, as many as 17,000 Cubans in Ethiopia who could be easily airlifted into Asmara.

Arrayed against the Ethiopians and their allies are perhaps as many as 25,000 EPLF guerrillas, 15,000 to 18,000 ELF fighters and 2,000 soldiers from a third, largely discredited group.

The nationalists say they do not need arms or ammunition. They have both from the Ethiopians over the years, especially thanks to an impressive string of victories last summer.

What they claim to need is food, blankets, and medicine for the 110,000 Eritrean refugees in the Sudan and the many more in Eritrea.

"Why does the West neglect these people? What is happening to the democracies, the Red Cross, the church groups," a nationalist spokesman asked. "What are they waiting for? If it continues like this, it will be your world that collapses, not ours."