Why Israel insists on following Camp David to the letter; It will not allow any pro-Palestinian wedge to be driven into peace process

Israel is determined not to be tied down by any conditions for dealing with the Palestinian problem beyond those accepted in the Camp David accords signed in 1979.

That is why the Israeli Government is being so difficult (in US eyes) about accepting the terms laid down by four European nations for joining the proposed Sinai peacekeeping force. Israel sees those terms as a pro-Palestinian wedge going beyond Camp David.

Under pressure from the US, the Israeli Cabinet gave qualified acceptance Nov. 30 to a compromise. Under this, Israel would no longer veto European participation in the force - as had once seemed likely.

The compromise involves a declaration to the effect that European participation in the Sinai force is based solely on Camp David.

The declaration simply ignores the Europeans' own statements about the basis on which they would contribute to the Sinai force. It remains to be seen whether the Europeans will still be willing to go ahead along these lines.

The new declaration was drafted in Washington Nov. 27 in talks between Israeli Foreign Minister Yitzhak Shamir and US Secretary of State Alexander M. Haig, Jr. Minor changes of wording - but not of substance - are requested by the Israeli Cabinet before it gives its definitive acceptance to the compromise.

The Israeli government was all the more perturbed at US pressure on it to accept Europeans in the Sinai force because of its timing. It came just as the failure of last week's Arab summit at Fez had removed from Israel - at least temporarily - an even more worrisome pressure: the Saudi peace plan.

The Saudi proposal is weighted in favor of the Palestinians, but not enough to save it from being torpedoed for the time being by Arab hardliners. As so often on past occasions, Israel was ''saved'' by the inability of Arab governments to come up with an agreed negotiating position.

But this time, the US and the Europeans were in the wings inhibiting Israel from exploiting the field abandoned by the Arabs. Hence Israel's current irritation.

The Israeli determination to stick to Camp David and spurn any amendment or wider forum stems from the Begin government's perception that Camp David offers an umbrella whereby, in return for giving Sinai back to the Egyptians, Israel can:

* Eventually annex the West Bank and Gaza - where most Palestinians currently under Israeli rule are concentrated.

* Ensure there will never be an independent Palestinian state on the West Bank.

* Concede to Palestinians an autonomy which went hardly beyond running their own municipal or village services.

* Avoid ever having to deal with the Palestine Liberation Organization (PLO).

The Camp David accords can be divided into two parts: one covering Israeli withdrawal from Sinai; and the other covering negotiation of ''full autonomy'' for the Palestinians. Israeli withdrawal from Sinai is due to be completed next April. The Palestine autonomy talks have in effect gotten nowhere.

A wide body of third-party opinion has already come to the conclusion that, within the present framework, the autonomy talks will never get anywhere. As far back as the summer of 1980, European Community leaders meeting in Venice voiced their doubts. Their Venice declaration called for PLO association with the talks and accepted the idea of a Palestinian homeland.

Both ideas are anathema to the Israelis. It is the Europeans' reaffirmation of their Venice views (albeit indirect) in connection with their participation in the Sinai force that Israel has till now found unacceptable.

Favorable US and European interest in parts of the Saudi plan, expressed this past August, only added to Israeli concern. It reinforced Israeli fears about pressures which might be exercised on Israel, if the outside world decided that an alternative had to be sought for the Camp David formula for Palestinian autonomy.

The US government, given its developing strategic relationship with Saudi Arabia, is bound to be sensitive to the humiliation which the Saudis have just suffered through rejection of their peace plan at the Arab summit in Fez, Morocco. Washington may therefore feel a need to help compensate the Saudis for this. But if the Arab moderates cannot come up with an agreed negotiating formula (as distinct from rhetoric), it is conceivable that the US Government might make proposals of its own to break the deadlock over the Palestinians. This possibility is perhaps Israel's greatest worry.

For most Israelis, at issue is their survival. So, in the meantime, their policy is likely to be resistance from the outset to every pressure in the direction of Camp David alternatives - plus intermittent reminders of their own spoiling power as the near-untamable Spartans of the explosive region in which they live.