Middle East diplomacy is heating up as the April deadline approaches for Israel's withdrawal from the last slice of Egyptian Sinai.
There is also an increase in military nervousness in the area - particularly in Lebanon - as this watershed date draws nearer.
It is a watershed date because, in theory at least, completion of Israeli withdrawal from Sinai brings the parties in the Arab-Israeli dispute to the next major stage in the search for an overall peace settlement. That stage is deciding the future of the Palestinians - and of the West Bank and the Gaza Strip, where most Palestinians under Israeli occupation are concentrated.
These territories (like Sinai) have been under Israeli occupation since the six-day war of 1967. So have the Syrian Golan Heights, whose future Israel sought unilaterally to decide by virtually annexing them last month.
In the overall scenario developing for the next stage of peacemaking, there are elements of hoping or working for the best, but preparing for the worst.
On the working-for-the-best side of the ledger should be listed:
* US Secretary of State Alexander M. Haig's direct involvement by traveling to Egypt and Israel last week. He will be returning to both countries next month. His aim is to smooth the path for the movement of the negotiating process from Sinai to the Palestinians.
* This week's agreement between Egypt and Israel on most of the major outstanding details surrounding Israel's final withdrawal in April. To secure that withdrawal, Egypt has sought to be as accommodating as politically possible in working out these details.
* The current visit to Saudi Arabia of the US State Department's top Middle East man, Assistant Secretary Nicholas A. Veliotes, and the scheduled visit there next month of US Defense Secretary Caspar Weinberger.
Preparing-for-the-worst entries in the ledger depend to some extent on the subjective judgment of those involved, either as initiators or possible targets. They include:
* Continuing deliveries to Israel and the beginning of deliveries to Saudi Arabia and Egypt of some of the more sophisticated new US aircraft. Egypt is also buying aircraft from France.
* The report in the Syrian government controlled newspaper, Tishreen, this week that the Soviet Union has agreed to supply Syria with more arms - without specifying what they would be.