President Carter doesn't have to - and shouldn't try to - hit a home run at the Mideast talks at Camp David this week. All he needs to do is advance the runners - which is to say, provide a framework for resumption of the Egyptian-Israeli talks.

For despite all the scare talk, there is no great danger - even if the conference collapses - of a new war or an Egyptian rapprochement with Russia. The only serious peril, the danger that has to be avoided, is that Egyptian President Anwar Sadat will retreat from his forward position on peace to a pan-Arab front against Israel.

Superficially, to be sure, the danger of another war looms large. Lebanon is a firecracker, and nobody can be certain where the sparks will light. Plestinian gunslingers are on the loose, trying to spoil Camp David by setting the Mideast ablaze.

But the controlling fact is Israel's overwhelming military superiority. The Israelis now have enough stores and weaponry to fight a three-front war for the next 90 days. They could easily take Cairo and Damascus. The leaders of Egypt, Syria and Jordan know all that, and they are at pains to avoid a conflagration.

As to an Egyptian rapprochement with Russia, it is highly doubtful that Moscow, having been once double-crossed by Sadat, would take him back. The Soviets have forged bonds with Sadat's main enemies in Libya, Iraq, South Yemen and other radical states. Moscow has been entertaining Syria's foreign minister, Abdel Halim Khaddam, as a kind of warning to Sadat not to take another shot at the Soviet Union.

Nor is there any reason to think Sadat would turn back to the Russians. He has crushed the pro-Soviet faction in Egypt, and used hostility to Russia to cement his base with the Egyptian military. Most important of all, he depends for subsidies on Saudi Arabia.

The Saudis, in the fullness of their anti-communism, would never countenance a revival of Egypt's connection with Russia. On the contrary, Prince Fahd, the Saudi ruler, has been pushing Egypt to south, not north, and to the right not the left. Fahd has been, for the past six months now, working for an Arab summit meeting. At such a session Sadat would finally drop the initiative he made in Jerusalem, and join with other Arab leaders in working to build enough strength to force Israel make a deal.

Indeed, the journey to Camp David was made precisely because Sadat, under Saudi pressure because Sadat, under Saudi pressure, began to harden his position just as Israel's Prime Minister Menachem Begin began to soften his. Bilateral negotiations between Israel and Egypt had been opened just after Sadat's historic visit to Jerusalem last fall. There was almost no problem between the two countries about eventual Israeli withdrawal from the Sinai desert and Gaza strip. The talks came undone when Begin refused to consider, even in principle, eventual negotiations for the return of the territory west of the Jordan River to Arab sovereignty.

Begin subsequently came under terrible internal and external pressure because of his intransigent stand. At a meeting of Israeli and Egyptian foreign ministers with Secretary of State Cyrus Vance in Britain in mid-July, the Israelis finally accepted the principle of negotiating on sovereignty over the West Bank. At that point Sadat changed his mind and broke off the talks once again.

Under these circumstances, it makes no sense to try to solve the whole problem at Camp David. Talk of stationing American troops on the West Bank or the Gaza strip - if not entirely the work of White House beavers eager to have the president score a big gain at Camp David - is at least premature. For the negotiations between Israel and Egypt have simply not got that far.

The trick at Camp David is to get the Egyptian-Israeli talks going once again. To that end, Begin ought to be pressed to say out loud and unambiguously that Israel accepts, in keeping with United Nations Resolution 242, the principle of withdrawal from all occupied territories including the West Bank of the Jordan.

Sadat ought to be pressed to accept that as his contribution to a general settlement of overall Arab conflict with Israel. Israel and Egypt should then go forward with the negotiation for a bilateral deal that would, by itself, cut down to almost zero any chances of the Mideast boiling into a new war.