By now, the world has seen such a long parade of fruitless peace plans for the Middle East that it should have become accustomed to watching them go nowhere fast.

So it is with the latest diplomatic initiative being pushed by Secretary of State James A. Baker III on his door-to-door sales trip this week through that chronically troubled part of the world.At this point, Israel and Egypt seem to be buying Washington's new-fangled package of negotiating procedures. But their acceptance is grudging. Besides, Baker faces much tougher sales resistance on the part of Syria, Jordan and the PLO.

In essence, the U.S. plan amounts to a peace conference as a one-time prelude to another, more meaningful peace conference. The prelude would involve the United States, the Soviet Union, Israel, Egypt, Syria, Saudi Arabia plus five other Persian Gulf states and the Palestinians. The idea is that such a conference would open the way to direct talks between Israel and the Arab states and between Israel and the Palestinians.

The plan's main attraction for Israel is the chance it offers to get hostile Arab nations to grant previously withheld recognition to Israel by talking with Israeli officials face to face.

But it's questionable whether that can be enough to get the Arabs what they want - which is to pry the West Bank and Gaza away from Israel and find a permanent homeland for the Palestinians.

Besides, as is so often the case with anything involving the Middle East, the new diplomatic effort involves complication within Byzantine complication.

For openers, the splinter parties that make up part of the ruling majority in Israel's government have threatened to bolt if Israel sits down with Palestinians. The departure of the splinter parties would necessitate new elections in Israel. New elections, in turn, would at least delay the preliminary peace conference.

Though some Palestinian leaders have met with Baker, they represent only one of the four major factions within the Palestine Liberation Organization. There are many others. The other three major factions have rejected the proposed new peace process. So have two formidable Moslem fundamentalist groups active in the territories.

This would seem to leave the latest Middle East peace effort pretty much back at square one despite Baker's good intentions. The Arabs still demand that Israel trade land for peace. But as long as the Israelis feel threatened by their neighbors, they are still understandably reluctant to give up the buffer provided by the fruits of their victory in the Six-Day War of 1967 - the West Bank, Gaza Strip and East Jerusalem.

The lesson should be clear: There's still no substitute for a mutual desire for peace. Consequently, a workable settlement in the Middle East seems bound to remain elusive as long as the continuing quest for it is based not on efforts to change people's hearts and minds but merely on the pursuit of novel procedures.