The Chinese invasion of Vietnam last week has provoked a level of fervor and denunciation not seen in Cuba since the U.S. "war of aggression" in Southeast Asia and the early days of Cuban support for African liberation movements.

Government-printed posters pledging Cuban support for Vietnam "to the last drop of our blood" appeared throughout Havana within hours of the invasion. Every day this week, the entire front page and most of the internal pages of Granma, the Cuban Communist Party newspaper, were filled with news of the fighting.

U.S. visitors on tour of a rural Cuban junior high school were greeted by students who cheered, "Hands off Vietnam."

At the same time, unlike the majority of the world's nations, Cuba has declined to criticize the Vietnamese invasion of Cambodia and has accused the United States of maneuvering to restore the fallen Pol Pot government there.

In an unscheduled speech Wednesday night to tens of thousands of cheering Cubans at a Vietnam solidarity rally, President Fidel Castro said that the United States and China have a "common cause" in Southeast Asia. The invasion of Vietnam, Castro said, "is a signal that the United States, as much as China, is looking for the reestablishment of the genocidal Pol Pot-Ieng Sary regime in Kampuchea," or Cambodia.

Their "policy objective" he said, "is to attack Vietnam, end all cooperation and solidarity with Vietnam and the [new] revolutionary Kampuchean government and surround Vietnam... from the north and south."

All this is occurring, Castro said, while the United States "appears to wash its hands of the problem."

As evidence of the outlined conspiracy, Castro noted that Chinese Vice Premier Teng Hsiao-ping had visited the United States immediately before the invasion. Castro said information published by an unnamed "foreign journalist" proved that Teng convened a meeting of the "Chinese [Communist] Party military commission" immediately upon his return, when the invasion decision was made.

Castro called the crisis "one of the most serious, if not the most serious world problem in recent times," all the more "repugnant" because it was perpetrated by a "traitor to the revolutionary movement."

He described Teng as a "caricature of Hilter," and cartoons in Granma every day this week have depicted Teng as a sharp-nailed figure on whose back rides a skeleton wearing a swastika armband and an "Uncle Sam" top hat.

Anumber of Cuban Communist Party Central Committee members were present at Wednesday night's rally, as well as the Vietnamese ambassador who smiled broadly from the stage and raised his hands in a "V for victory" sign. Similar rallies have been reported throughout the island.

While other Vietnamese solidarity posters here say that "the commander in chief [Castro] orders" Cuban support, and there are rumors here of a military mobilization, informed observers believe it unlikely that Cuba would actually offer more than token physical support to the Vietnamese troops.

The situation rather provides an opportunity, of a type that has become increasingly rare since Cubans have ceased to fear an invasion of their island, for mobilization of Cuban emotions against a common enemy and moral support for struggling revolutions. The Cuban people have long identified with the Vietnamese, because of what they view as their joint struggles against the United States and their largely self-won victories against "aggression."