Israel expects the Reagan administration, fresh from a landslide victory in Tuesday's presidential elections, to broker an agreement between Syria and Israel that will enable Israel to withdraw from south Lebanon.
That view was expressed Wednesday by Simcha Dinitz, a former Israeli ambassador to the United States, on Israel Radio. Israel is scheduled to begin military talks today with the Lebanese to arrange a pullout.
An agreement with Syria, however informal, would include assurances that Syria will not move from its positions in eastern Lebanon and that Syria will prevent Palestinian guerrillas from infiltrating to attack northern Israel, should Israel pull out of Lebanon.
The Israelis say such a ''gentlemen's understanding'' with Syria, the main power broker in Lebanon, can be arranged only through the good offices of the US. But the Reagan administration was keeping a low profile in the region before Tuesday's elections.
Now the Israelis expect Reagan to reenter more aggressively an arena where his administration suffered perhaps its worst foreign relations disasters. But, analysts agree, there is little likelihood of an overall Mideast peace settlement in the next four years. Israeli officials say privately that the bombings of US facilities in Lebanon and Leba-non's abrogation of the US-arranged accord on Israeli withdrawal from Lebanon have strengthened US-Israeli ties.
''The Americans got burned badly by the Arabs in Lebanon,'' says an Israeli official. ''(Secretary of State George) Shultz believes now that Israel is the United States' only reliable ally in the Middle East.''
One possible friction point between a second Reagan administration and Israel is the Reagan initiative, the overall Mideast peace plan introduced in 1982 that has been all but shelved. The plan called for formation of a Palestinian ''entity'' on the West Bank and Gaza Strip in confederation with Jordan.
Reagan told the United Nations in September that his administration stands behind the initiative. The government of Prime Minister Menachem Begin had rejected it. The new government has yet to take an official stand.
Some Arab moderates, such as Jordan's King Hussein, are thought to be hoping that Reagan will now pursue the plan more actively. Hussein and Palestinian leader Yasser Arafat had initially rejected it.
A Western diplomat scoffs at the notion that Reagan will pressure Israel to make concessions to the King and trade the occupied West Bank for peace.
''What pressure is the President going to bring?'' the diplomat asks rhetorically. ''What pressure has the US brought to bear against Israel in the last four years?''