Israel said today that Lebanon can guard against the possibility of a new cycle of "terrorism and violence" only by agreeing to Israeli conditions for withdrawing its troops from Lebanon.

An Israeli Foreign Ministry "policy background" paper given to reporters covering the deadlocked withdrawal talks near here, repeated Israel's claim that United Nations peace-keeping forces and troops in the multinational force had been unable to prevent "terrorist infiltrations into southern Lebanon and the dangers of destruction to both countries."

"There can be no substitute for iron-clad security guarantees reinforced by good-neighborly relations between the two countries," the statement said.

The warning followed a weekend of escalating violence that included the shelling yesterday of East Beirut as fighting broke out between Christians and Moslem Druze militiamen in the Israeli-occupied hills overlooking the city.

Attention also was drawn here today to reports that Israeli Defense Minister Ariel Sharon had applied strong pressure on the father of Lebanese President Amin Gemayel to agree to Israel's conditions during a meeting in Lebanon last week.

Israeli radio reported yesterday that Sharon told Pierre Gemayel that he "doubted whether his son, Amin, would continue as president if he constantly took orders from Syria, Saudi Arabia and the PLO."

Sharon also told the elder Gemayel, who is president of the rightist Christian-dominated Phalangist Party, that Israeli troops may withdraw from the hills overlooking Beirut and "leave the Christians to their fate" if the Lebanese government continues to reject Israel's demands, the radio reported.

Western sources said Sharon was even more blunt in his private conversations with Gemayel and the Lebanese Forces Christian militia.

The sources said Sharon warned that the Lebanese Christians had to choose between Israel and the United States, which is supporting the Lebanese in their resistance to demands for formal ties and trade between the two countries.

If the Christians choose the United States, Sharon reportedly told them, they should not expect Israeli help if they are threatened later by the Syrians.

Meanwhile, Lebanese Army soldiers today turned back Israeli patrols trying to enter West Beirut and the Palestinian refugee camp of Burj al Barajinah in incidents similar to ones that caused friction between U.S. Marines and Israeli troops earlier this month.

The Israelis, apparently looking for gunmen who killed an Israeli soldier and wounded four others yesterday, turned away without argument both times after Lebanese Army soldiers refused to allow them to pass checkpoints.

Local press reports here, quoting security sources, estimated that at least seven persons were killed and 13 others wounded in the artillery duels in the mountains overlooking Beirut this weekend. The only report of a casualty in East Beirut was of a French priest who was killed when more than 150 shells fell on commercial and residential neighborhoods of the Christian sector of the capital.

There were scattered rocket exchanges in the mountains today but no reports of casualties.

The "policy background" paper issued by the Israelis said the Lebanese were resisting normalizing relations with Israel and agreeing to trade and open borders because of Arab pressure--"one more indication that the Arab world does not want peace with Israel."

"If, indeed, peace were its goal, then surely it would not consider the movement of goods and people between two neighbors as something akin to treason, nor would it consider the negotiations which are now taking place in such a friendly atmosphere as something to be castigated and condemned," the statement said.

When today's eleventh session of the talks adjourned, negotiators were able to report only that they had discussed the issues "intensively" and "advanced" in "bridging gaps."