The shape of the island nation of Sri Lanka -- like a teardrop off the southern tip of India -- suggests the fate that has befallen this onetime tropical paradise. And the bloody ethnic violence wracking the country belies the connotations of the ancient Arabic word for the spice-laden island: Serendip.

The former colony of Ceylon gained its independence from Britain in 1948, but the British rulers had sown the seeds of the present conflict between the dominant Buddhist Sinhalese and the Hindu Tamil minority.

The British imperial administrators showed a definite favoritism toward the Tamils, and placed them in positions of influence in the colonial bureaucracy. After independence, the Tamils were eased out of their powerful government jobs, and salt was poured on the wounds by the adoption of Sinhalese as the official language in 1956.

The Tamils were understandably aggrieved, but their leaders counseled peaceful accommodation. After all, they reasoned, the country was a democracy with a freely elected parliament.

How, then, did Sri Lanka reach its current state of chaos and bloodshed? Since the Tamil guerrilla uprising in 1983, thousands have been killed -- most innocent victims of terrorist atrocities and Sinhalese reprisals. The Tamil militants are now holding the northern Jaffna Peninsula, insisting it is the nucleus of a separatist state.

From intelligence sources and Dale Van Atta's recent trip to the unhappy country, we have uncovered disturbing evidence of significant foreign involvement in the Tamil insurrection.

The most significant meddler in the Sri Lankan situation is Prime Minister Rajiv Gandhi of India, who has encouraged or at least allowed the secret funding, training and supplying of the doomed Tamil rebels. But other international mischief makers have weighed in with support for the Tamil terrorists, whose slaughter of civilians has put them beyond the pale.

These supporters include North Korea, Libya, Zimbabwe and the Palestine Liberation Organization. Not surprisingly, Israel is advising the Sri Lankan government how to combat the PLO-trained guerrillas.

A secret CIA report says it's clear that most Tamil leaders were initially inclined to avoid violence, but were subjected to ''great pressure from an impatient and militant Tamil youth.''

The young hotheads, still known by the older moderates as ''The Boys,'' were given more than inspirational talk by their leftist tutors. The most promising young men were sent off to receive guerrilla training by the Libyans and the PLO. Many Tamil leaders are unapologetically Marxist.

As the violence escalated, the beleaguered government in Colombo turned to its Western friends for help. Former CIA official Vernon Walters, now U.S. ambassador to the United Nations, was one of the first on the scene. He secretly advised the Sri Lankans to get help from Israel.

Israel responded with some arms and two dozen counterterrorism experts. The British government has not helped Sri Lanka directly, but the Colombo government has hired some former members of the British Special Air Services through private companies.

But these minuscule Western efforts pale before India's support for the Tamils. There are 50 million Tamils in India. And whatever Gandhi may say in denial, the Tamil Tigers have received tremendous support from India, including sanctuary when the Colombo military closes in on their strongholds in Sri Lanka. The Indian Air Force delivers tons of ''humanitarian'' supplies to rebel-controlled areas.

The Tamils had legitimate grievances. But their argument has been drowned in blood. Their long-term goal -- to partition an island that has never been divided -- is economically unsound. Their methods are morally outrageous. The Tigers must be tamed -- with no more outside interference.