Last Indian Troops Leave Sri Lanka : Peacekeeping: Nearly three years of fighting failed to crush Tamil separatists. It was a hard lesson for New Delhi.

Sweltering and glum-faced on the shores of China Bay, the last of the Sikh Light Regiment marched single-file ahead of the final contingents of Gurkhas and paratroopers onto a waiting Indian navy troop ship early Saturday, as India ended its longest and most controversial foreign military adventure.

The Sri Lankan Navy Band played “Auld Lang Syne,” and there were speeches of praise and thanks all around.

But, as the last few hundred of India’s 50,000-member “peacekeeping force” withdrew from its neighbor, it was clear that the world’s fourth-largest army had learned the lessons of Vietnam and Afghanistan the hard way.

After nearly three years of fighting that left at least 1,155 Indian soldiers dead, thousands more injured and the nation of Sri Lanka devastated, South Asia’s principal power failed to crush a guerrilla force of Tamil separatists that was less than one-twentieth the size of the Indian force.

As the last of the Indian troops boarded their ship for home, only the insurgents whom India had been called in to defeat were claiming victory.

“It is really a victory for us,” said a spokesman for the Liberation Tigers of Tamil Eelam at the rebels’ newly opened political office in this northeastern port. “The Indian army could not defeat the Tigers. And in the end, the Indian peacekeeping force could only keep the peace by withdrawing.”

But neither the Indians nor the Sri Lankans, who called for the peacekeepers in 1987 to help put down a violent Tamil insurgency, were conceding defeat.

Speaking to the Indian soldiers aboard their troop ship Saturday, New Delhi’s ambassador, L. L. Mehrotra, tried to put the best face on things. He spoke of the Indians’ effort as “a job well done,” adding that the departing force “leaves Sri Lanka with a sense of fulfillment.”

An Indian official who asked not to be named was more contrite. Comparing India’s experience here to those of the United States in Vietnam and the Soviet Union in Afghanistan, he said, “The main difference is, we came out faster so it’s easier to cover up.”

Sri Lankan Foreign Minister Ranjan Wijeratne, whose government has been demanding the pullout for more than six months, spoke in a similar tone to the departing troops.

“We have to face realities. . . ,” he said. “You made a great sacrifice. But now, our hope is that we will be good neighbors, friendly neighbors. . . . We don’t have to fight each other for that.”

Later, a reporter asked Wijeratne if he was glad to see the Indians go. “Yes,” he replied. “After all, the purpose has been served.”

Many independent analysts, who are nevertheless critical of the Indian military adventure, agreed with Wijeratne’s assessment.

“The fact remains that today . . . Sri Lanka is more peaceful than it has been in nearly eight years,” one diplomat said. “What India could not achieve by staying, it has done by leaving.”

Indeed, in this island nation of 15 million people, which counted 30,000 lives lost in a two-front insurgency last year alone, the current weekly toll of about 40 dead is seen by many as a relief and a precursor of even less violence.

In northern areas that include Trincomalee, an effective truce by the Tamil insurgents has halted the main ethnic conflict that touched off Sri Lanka’s cycle of violence nearly a decade ago.

Tamils, mostly Hindu and making up 18% of the population, complained of discrimination by the Buddhist Sinhalese, who are 75% of the population and dominate the government and military.

The conflict flared in July, 1983, when a Sri Lankan army convoy was ambushed by the Tigers, the armed force of the island’s ethnic Tamil minority.

The fighting escalated sharply through the years, and India, home to 54 million ethnic Tamils, persuaded former Sri Lankan President Junius R. Jayawardene in 1987 to allow Indian troops into Tamil-dominated regions, ostensibly to protect the Tamils.

But the Tigers promptly began fighting the Indian army, and after Jayawardene retired, President Ranasinghe Premadasa began demanding an Indian withdrawal.

The truce with the Tigers in the north coincides with relative calm in the south, where a government-linked purge last year crippled a leftist, Sinhalese insurgency.

“There is a certain optimism now, based on an expectation that there will be peace,” said Neelam Tiruchelvam, a Tamil lawyer and respected analyst in Colombo. “But this expectation will be destroyed if we have a . . . confrontation between the Sri Lankan government and the Tigers now.”