A breakdown in negotiations between Sri Lanka's Tamil rebels and India tightens the screws on this nation's embattled President - and is a diplomatic blow to Indian Prime Minister Rajiv Gandhi. Calling off cease-fire talks last week, the Liberation Tigers of Tamil Eelam have vowed a ``long struggle.'' The rebel Tigers, as they are commonly known, termed last July's India-Sri Lanka pact to end the civil war here ``a charter of servility,'' and accused the estimated 50,000-60,000 Indian ``peacekeeping'' force of atrocities. Only last August, the Indian troops were warmly received as protecters by Tamils in northern Sri Lanka.
The turnaround is a setback to India's role as regional crisis-manager. And it is more than likely to place President Junius Jayewardene's government under even stronger pressure from the island's ethnic Sinhalese-Buddhist majority.
While the Tigers continue their five-year-old armed campaign for an independent Tamil homeland, hard-line Sinhalese reject the accord on grounds that it makes too many concessions to the Tamils and allows for Indian interference.
In parliamentary by-elections July 14, Mr. Jayewardene's United National Party retained three seats with greatly reduced majorities, and lost a fourth badly.
``The trend is clear,'' claims former Prime Minister Sirima Bandaranaike. As leader of the Sri Lanka Freedom Party, she is regarded as Jayewardene's main rival in presidential polls to be held by late December. Her campaign blasts the pact and ``foreign troop presence.''
Under the pact, Indian troops were to leave after disarming Tamil rebels. The Tamils, in turn, would get more autonomy through elected ``provincial councils'' in the Northern and Eastern Provinces, which they claim as their eelam (homeland). The north is almost 100 percent Tamil. But the east has a sensitive ethnic mix - 42 percent Tamil, 33 percent Muslim, and 25 percent Sinhalese.
Fears of antagonizing Sinhalese - and the Muslims in the east - resulted in a compromise: A 12-month merger to be followed by a referendum in the east on whether to make the union permanent.
But there has been a backlash of hard-line Sinhalese opinion. In the past year, hit squads from the Janata Vimukti Peramuna (People's Liberation Front or JVP) have gunned down over 200 backers of the accord. Jayewardene narrowly escaped a grenade attack last year.
The Tigers - who were negotiating with India's intelligence agency - reportedly want Mr. Gandhi to press Jayewardene for more autonomy and a presidential proclamation offering a single council for their ``traditional, indivisible homeland.'' Such offers would amount to political suicide for the Sri Lankan President.
The Tigers have also asked Gandhi to order Indian troops to halt their onslaught with heavy armor and helicopter gunships on guerrilla jungle hideouts.
The Indian Army has a different perception of the problem from the intelligence agency, which argues strongly for a negotiated settlement to prevent India from being sucked into a protracted war.
The Tigers will be ready to re-open talks after ``they have been given another bashing,'' an Indian brigadier suggests. ``Negotiate from a position of strength.''
But if the Army gets too tough, there could be an uproar in India's southern Tamil Nadu State. Home to 50 million ethnically related Tamils, Tamil Nadu has backed the accord. If the Tigers are viewed as getting the short end of the deal, however, Tamil Nadu could resume providing sanctuary and arms to them.
``It is not only Tamil Nadu opinion but the national consensus Mr. Gandhi must worry about,'' says a Sri Lankan diplomat who served in New Delhi. ``The Indian parliament may demand that the troops be withdrawn'' if the Tigers seem likely to keep their ``pledge of a long struggle.''
The Army - which, by some estimates, is spending $1 million a day - has already lost about 460 men. Anti- as well as pro-Gandhi politicians worry about an ``Indian Afghanistan.''
``The Indian Army is the sacred cow of the Indian elite,'' says Sri Lanka's leading India-watcher, Prof. Shelton Kodikara. The prestige of the world's fourth largest army is now at stake, he says.