"Of course, there may be some crossing of the border, but that cannot be helped. when we attack, they withdraw to the other side of the border, then later they return. So in that case the war goes on and on. We can't just stand there watching it." "The primary objective of the assistance we give to our friends is to help the latter decide their own destiny . . . . We must wholeheartedly help our friends to build a comprehensively firm and strong army, especially in the political and moral domains, and in leadership and command capability . . . "

They could almost be statements from the Vietnam War era: Gen. William Westmoreland on the Vietcong's use of cross-border sanctuaries, or former defense secretary Melvin Laird on the aims of "Vietnamization."

But the words are those of two senior officials of the Vietnamese Communist Party: Hoang Tung, a member of the party secretariat, and Gen. Le Duc Anh, a member of the Politburo. Tung, in an interview, was justifying recent Vietnamese incursions into Thailand in attacks on Cambodian guerrilla bases, and Anh, in a lengthy article, was stressing the need for the Cambodian Army to play a greater role in the fighting.

The war they were discussing, now in its seventh year, has sometimes been described as "Vietnam's Vietnam."

It is an analogy that leaders in Hanoi reject.

"This comparison is not correct," said Gen. Tran Cong Man, the editor of the Army newspaper Quan Doi Nhan Dan. True, he said, Vietnam is now on the other end of guerrilla war, and "there are some complicated problems in Cambodia that must be settled." But, unlike the Vietnamese who were fighting the Americans, he argued, the Cambodian guerrillas lack popular support, and without it "they cannot succeed."

Yet there is a basic parallel. Instead of the Americans, the Vietnamese are now the foreign troops fighting dedicated guerrillas, who claim nationalist and anticolonial credentials, in an increasingly frustrating war that drags on year after year with no end in sight.

Even the term "Vietnamization" is still in vogue. Only now it refers not to Washington's efforts to hand responsibility for the war over to the South Vietnamese, but to what Cambodian resistance leaders charge is Hanoi's attempt to virtually colonize their country by sending in huge numbers of Vietnamese settlers.

Indeed, Hanoi's own efforts at "Cambodianization" of the conflict by building up the administration and army of its proteges in the Cambodian capital, Phnom Penh, appear to have been a disappointment. Today that Vietnamese-installed government -- the People's Republic of Kampuchea led by President Heng Samrin -- has no international recognition outside the Soviet Bloc and India, its writ in much of the country is questionable and its fledgling Army of 30,000 is considered hardly any closer to taking over security responsibilities from the Vietnamese than it was four years ago.

That the Vietnamese are having problems can be discerned between the lines of statements such as the article by Gen. Anh in December in the Army theoretical journal. Anh, who is reportedly in charge of military operations in Cambodia, laid surprising emphasis on the need to improve security in the interior as part of what he called "a fierce revolutionary struggle."

He wrote that, "taking advantage of Thai soil," Cambodian guerrillas had "set up logistical bases, opened points of entry at the border and created infiltration corridors to pour forces and weapons inland for guerrilla and sabotage activities, seizing land, controlling the population, building counterrevolutionary forces and so forth."

Anh called for greater efforts to get Cambodians "to participate in the building of militia and self-defense forces."

Ultimately, Anh said, "The success of the Cambodian revolution must be decided upon by the Cambodian people themselves under the leadership of the Khmer People's Revolutionary Party." But he cautioned that the "struggle is still long and complicated."

What all this amounts to is that 10 years after Hanoi's troops defeated the U.S.-supported Saigon government in South Vietnam, the Vietnamese are locked in another war with no light at the end of the tunnel.

The conflict is not discussed much in Hanoi. There is no sign of war fever, or of the sort of propaganda barrages that Vietnamese authorities regularly unleash against their main enemy, China. In fact, the leadership seems to play down the Vietnamese involvement by referring to the "limited contingent" of troops in Cambodia as "volunteers" fulfilling their "lofty international duty" by helping the Phnom Penh government defend itself against the Chinese-backed "Pol Pot clique" and other "reactionaries."

The reference is to Cambodia's widely reviled Khmer Rouge guerrillas of ousted Communist dictator Pol Pot, and two noncommunist resistance groups led by Prince Norodom Sihanouk, the former Cambodian monarch, and Son Sann, a prime minister in Phnom Penh in the 1960s. The three parties are uneasy partners in a loose coalition that is recognized by the United Nations as Cambodia's legal government. Hanoi First Backed Pol Pot

When the Khmer Rouge seized power in Cambodia in April 1975 from the U.S.- backed Lon Nol government, which had overthrown the neutralist Sihanouk five years earlier, Hanoi hailed the takeover as "a great victory and a fine one."

As a result of "a resolute and glorious revolutionary combat," said the May 1975 issue of the government's English-language monthly Vietnam Courier, "radiant prospects of social renovation and economic and cultural advance have been opened for the Khmer people." In apparent reference to Vietnamese support for the Khmer Rouge, the editorial also claimed a share of the credit for the guerrillas' victory by attributing it to "the fraternal solidarity in combat that unites the Khmer, Lao and Vietnamese peoples."

By the time the editorial was published, the Khmer Rouge had already launched a ruthless scheme to destroy Cambodia's old society and replace it with an entirely new system of "total communism." The result was the evacuation of cities, forced labor in the countryside, the abolition of currency, religion and all major institutions and a reign of terror and destruction that left an estimated 1 million to 2 million Cambodians dead.

Then, in December 1978, after a series of border incidents, the Vietnamese invaded Cambodia and within two weeks overthrew the Khmer Rouge leaders they had once lauded. In their place, the Vietnamese installed a client government made up largely of Khmer Rouge defectors, among them the new president, Heng Samrin.

Ravaged by famine, Cambodian refugees streamed toward the western border with Thailand, and the Khmer Rouge appeared on the brink of annihilation.

However, China, which by now had fallen out with Vietnam, stepped in to aid the Khmer Rouge with the acquiescence of Thailand, which feared having the Vietnamese on its borders. Thailand and its Southeast Asian partners also backed the formation of noncommunist Cambodian resistance groups and prodded them to coalesce with the Khmer Rouge to clean up the latter's image and help retain U.N. recognition.

That recognition, which is supported by the United States, is based on the principle that no matter how despicable Khmer Rouge rule may have been, the Vietnamese invasion and continued occupation of Cambodia represent a violation of international law that cannot be tolerated.

In response, the Vietnamese have been playing for time with a policy of annual troop "withdrawals" -- denounced by Thailand and others as mere "rotations" -- coinciding with continued military campaigns against the guerrillas and diplomatic efforts to promote recognition of the Phnom Penh government.

But the guerrillas are proving hard to eradicate, and the "Vietnam War" analogies for International Human Rights, the People's Republic of Kampuchea now appears to be rivaling the Khmer Rouge as a human rights violator. "The rule of law is not respected in any serious sense in the People's Republic of Kampuchea," the group concluded in a December 1984 report. "For the hundreds or perhaps thousands of political prisoners who inhabit its jails, beatings are commonplace and more sophisticated forms of torture usual."

As for the Khmer Rouge, the report said, "Today, in the areas we investigated, it would appear that the murderous practices of the mid-1970s are no longer the order of the day. But severely restrictive controls over daily life remain a pervasive reality of Khmer Rouge society, and allegations of occasional instances of brutality and deaths during detention persist."

The increased activity in the interior indicates that, more than six years after their widely reviled regime was swept from power, the Khmer Rouge have been drawing support from at least some Cambodians, notably in rural areas, according to both diplomats and noncommunist resistance leaders. Vietnamese Presence Resented

This comeback of sorts is attributed less to Khmer Rouge penitence than to growing popular resentment of the presence of an estimated 160,000 to 180,000 Vietnamese troops and increasing numbers of Vietnamese settlers.

Specifically, Cambodian peasants lately have especially resented being dragooned by the Vietnamese into forced labor teams and sent to the Thai-Cambodian border to build a network of roads and defensive barriers, according to western relief workers in Cambodia. The network is aimed at improving Vietnamese logistics in the border area and preventing guerrilla infiltration. The Vietnamese have acknowledged mobilizing "tens of thousands" of Cambodians for the construction work, but insisted that it was voluntary and not forced labor.

One side effect of the project, said one relief official, has been the spread of a resistant strain of malaria, common along the border, to workers from other provinces.

"The forced labor and the malaria have caused a lot of animosity toward the Vietnamese," the official said. "The Vietnamese have gained a lot militarily in the border area, but the toll has been very heavy in terms of the health of Cambodians."

An influx of settlers also has raised indignation and suspicion among some Cambodians that crowded Vietnam, with a population of 60 million to Cambodia's estimated 6 million, has expansionist designs on its potentially bountiful neighbor.

According to Prince Sihanouk, the head of the three-party resistance coalition, there are now about 600,000 Vietnamese settlers in Cambodia. The Vietnamese and Phnom Penh governments insist the number is far lower. As of mid-1983, they say, 56,000 Vietnamese who formerly lived in Cambodia had reestablished residence there, amounting to about 10 percent of the Vietnamese population in Cambodia before the Lon Nol and Khmer Rouge regimes.

However, recent visitors to Cambodia have reported seeing Vietnamese settlers who clearly were newcomers and who spoke no Khmer, the name of the language and ethnic group of the Cambodian majority.

While many of the Vietnamese may cross into Cambodia on their own from southern Vietnam in search of economic opportunities, some apparently benefit from government support.

One Cambodian barber in Phnom Penh told a visitor recently, for example, that he had been obliged to take on a Vietnamese partner to get back the shop he had been forced to abandon in 1975 when the Khmer Rouge took over.

Another Cambodian shopkeeper told an Italian correspondent in a southern suburb of Phnom Penh that 20 to 30 Vietnamese a day were arriving in trucks to take up residence there. While they were talking, the reporter witnessed the arrival of one such truck.

A western relief agency official who lived in Phnom Penh a few years ago said after a recent return trip that he was "amazed" at the number of new Vietnamese settlers he saw. "The traders of farm produce tend to be Vietnamese, not Khmer anymore," he said.

"People are very angry about it," said another recent visitor of the Cambodians he met. "They talk about the Vietnamese more and more."

Sihanouk, who is often asked about the prospect of the Khmer Rouge returning to power, said in an interview in Thailand in February: "I have only one nightmare about the future of Cambodia, that it could be 'Vietnamized' and lost to the Cambodians, that it could become a second South Vietnam." (Until the Vietnamese conquered it in the 18th century, the Mekong Delta was part of the Khmer empire.)

Sihanouk acknowledged that "if the Cambodian people were left only with choice between Pol Pot and the Vietnamese, they would choose the Vietnamese."

But Sihanouk insisted the Khmer Rouge regime can never come back to power, if only because the Vietnamese would never allow it. The solution, he said, is a four-party coalition including the three resistance factions and the Heng Samrin government, but this has been rejected by all sides.

In any case, Sihanouk said, Pol Pot is ill. But specifics of the condition and whereabouts of the former dictator, who gave up his government posts after 1979 but still commands the Khmer Rouge army, are unknown. Khmer Rouge officials have said he is inside Cambodia leading his troops. If so, it is generally assumed he would be somewhere in the Cardamom mountain region of southwestern Cambodia.

The terror unleashed by the Khmer Rouge still evidently haunts Sihanouk, but so does the prospect of "a Vietnamese fait accompli in Cambodia."

"I continue to suffer in my heart," he said. "But since the Vietnamese are still there, we have no choice."