Jerusalem — For the moment at least, the likelihood of an Israeli invasion of southern Lebanon seems to have passed.
So far, American pressure appears to have kept Israeli forces from moving out of encampments along the northern border and engaging Palestinian guerrillas.
Yet Israeli officials and diplomats in Jerusalem agree that a single terrorist attack against Israeli targets - or possibly even against Jewish targets in Europe or North America - that is traceable to Lebanese-based Palestinians, would give Israel enough reason to launch such an invasion.
Until now, the frequent bomb blasts in Israeli territory have simply been ignored by the government as grounds for breaking the seven-month-old cease-fire.
In the meantime, a Cabinet-level row in Israel Feb. 17 between Deputy Prime Minister Simcha Ehrlich and Labor opposition leader Moshe Shahal gave analysts little doubt that Israeli leaders had been seriously contemplating an invasion in recent days.
Mr. Shahal accused Mr. Ehrlich of informing journalists of the invasion and then boasting that by leaking the plan, he had caused Prime Minister Menachem Begin's Cabinet to reject the idea of a military strike. Mr. Ehrlich called the accusation a ''base slander.''
But instead of last week's rumors about an imminent invasion, most official Israeli attention this week has been focused on ending the tiff between Israel and the US over possible US sales of military jets and mobile antiaircraft missiles to Jordan.
There seems to be at least tacit recognition among Israeli policy specialists of the effect on Washington of Israel's bombing raids last year on Baghdad and Beirut, and virtual annexation of the Golan Heights in December.
A move into southern Lebanon, in defiance of US warnings, the reasoning goes, might be a vastly more damaging blow to Israel's standing with the Reagan administration. That in turn could contribute to a much-discussed realignment of US Middle East alliances - an alignment away from Israel.
So for the time being, Israeli officials seem to be on their best behavior. As one specialist told the Monitor: ''We are now in a holding pattern with Washington. That is not good. A holding pattern means erosion and the wrong reading of signals in Saudi Arabia, Syria, and elsewhere in the Arab world.''