No more complicated and difficult an operation can be imagined than the evacuation of some 6,000 PLO fighters from west Beirut. Yet US special envoy Philip Habib appears to be doing the impossible of putting a plan together and gaining its acceptance by Israel and the Arab countries. If his tireless diplomacy succeeds, he will manage to spare Beirut a final Israeli assault that would take an even higher toll in lives and devastation. He will also restore credibility to United States leadership in the Middle East and put the Reagan administration squarely in the middle of what will be a new urgency to find a solution to the Palestinian problem.
Everyone must ardently hope and pray that he succeeds. Indeed he has accomplished much already. The Arab states, which have been conspicuous by their lack of support and sympathy for their Palestinian client, have begun to rally around. A number have agreed to provide a refuge to the PLO guerrillas. Israel has accepted the evacuation plan ''in principle.'' So far, so good.
But it is only prudent to recognize the diplomatic pitfalls in the operational details yet to be worked out. The Begin government demands a list of names of the PLO fighters. It also insists that most of the guerrillas pull out before multinational peacekeeping forces take up their positions (so that the latter do not become a shield for the PLO). Either of these issues could easily provide the pretext for unravelling the plan.
Even the countries of destination are not firmly in place. The US would like Egypt to be a participant, clearly because it would be a moderating influence on the PLO and because Egypt would then be closely involved. But President Mubarak reportedly is insisting on a price -- linking departure of the PLO with a US commitment to Palestinian self-determination, a demand which is not unreasonable.
Obviously it will take a tremendous amount of good will on all sides to conclude the plan and bring it to fruition. It will take an even greater effort and determination to move forward the peace process if and when the PLO is dispersed. Brute force has prevailed for the moment. There is no doubt that Israel's unrelenting military pressure has persuaded the weakened PLO to agree to leave. (Perhaps quiet US assurances not to drop the Palestinian question also played a role.) But Israeli force will not wipe out Palestinian nationalism , which Israel's invasion of Lebanon can only enhance, nor destroy the Palestinian national movement.
Washington's immediate task is to get the PLO out and save what is left of Beirut. There is now some optimism that that can be accomplished -- a tribute to Mr. Habib's skills. The harder task will be to look beyond Beirut with a vision of a larger and permanent peace.