Lebanon: two symbols of tension fade

For the United States the pullout this week of the last Marine combat forces in Beirut represents the end of an unhappy segment of American history. For Lebanon it is another in a series of modest steps, now proceeding in fits and starts, with the aim of producing a less divided, more normal atmosphere, at least in Beirut.

The bulk of the American combat soldiers left months ago. On Monday the final contingent - no more than 100 - began leaving Beirut, where it had been guarding the temporary US embassy.

The withdrawal comes about because the American embassy is moving into a new, more secure building. US officials evidently believe it can be protected by the same size of Marine security detachment - 15 - that is on duty at other embassies around the globe. This is a welcome return toward the normal way that American government conducts its business in other nations.

For months the US was operating in quite a different manner, intending to be a peacekeeper but ultimately seen by the Muslim majority as on the side of the Christian and Israeli adversaries. American troops remained bunkered down in their exposed positions near the Beirut airport, as US diplomats sought to exert American influence to produce peace in the war-torn nation.

Ultimately America realized what others, including many Lebanese, had increasingly been saying - that there was no longer a role for the US to play in restoring peace to Lebanon. In February of this year the bulk of the American marines were withdrawn to ships offshore.

Today the situation in Beirut, as in the rest of Lebanon, is far from perfect. The weekend saw a gun battle between two rival militias, and an artillery duel.

Yet diplomatically the need remains what it was in February: The US is without a significant diplomatic role, and the leadership in rebuilding the Lebanese nation must be taken by the Lebanese. This weekend the Lebanese government doggedly continued, despite the gunfire, to carry out one part of its peace plan - by tearing down more of the ''green line'' which divides the Christian east sector of Beirut from the Muslim west.

Much more must be accomplished in the difficult task of ending the suspicion and hostility between Beirut's factions, necessary if unity is to be produced. But bulldozing barricades and withdrawing unneeded combat forces are in themselves encouraging steps.