Jerusalem — Arab-Israeli tensions are mounting as the April 25 deadline approaches for Israel's final withdrawal from Sinai.
At time of writing, the consensus of diplomats and officials here was that this part of the Camp David accords would go ahead on schedule. But growing anxiety was expressed about:
* The possibility of an imminent Israeli invasion into Lebanon. The Reagan administration announced Monday that Deputy Secretary of State Walter Stoessel was being sent on an urgent mission here to try to ''reduce tensions.''
* Some last-minute flurries in discussions with Egypt over the Sinai withdrawal plan. Israeli officials raised objections to what they call Egyptian aid for the Palestine Liberation Organization (PLO) in Gaza, to an Egyptian speech to a non-aligned meeting in Kuwait, and to Egyptian troop strengths in Sinai. Mr. Stoessel will join Assistant Secretary of State Nicholas Veliotes, already in Israel, in an effort to sort out final details of the Sinai withdrawal.
* A sudden outbreak of sometimes-violent Palestinian demonstrations in the Israeli-occupied territories. The protests were triggered by an April 11 shooting spree by an apparently mentally disturbed Jewish-American gunman at the Muslim Dome of the Rock shrine here in which two Arabs were killed. In a further reaction April 12, the Supreme Muslim Council called for a seven-day general strike in the occupied territories.
All of these developments are considered serious. But at this writing none seemed likely to actually derail the Sinai exchange. Thereafter, the fate of the other occupied territories--Gaza, the Golan Heights, the West Bank - will become the center of attention. Israel's goals for these were outlined to the Monitor over the past week by Israeli strategists:
The Gaza Strip. Israel has had many fewer problems ruling Gaza over the past 15 years than it has the West Bank. This is because Gaza Arabs are isolated from those in the West Bank and because Ariel Sharon, now Israel's defense minister, dealt severely with Gaza in 1967 and 1971.
A leading Israeli specialist on affairs in the occupied territories sees the Gaza as ''easier to manage and always more moderate'' than the West Bank. Gaza is also more economically depressed and contains few significant religious sites prized by Jews.
''We feel that Gaza is much closer to Egypt than the West Bank ever was to Jordan,'' says Zvi Elpelleg of Israel's Shiloah Institute. ''Fewer of the institutions there are connected with the PLO. We are better understood there.''
Israel's ultimate aim, therefore, is not to annex Gaza but to either give it to Egypt or institute some form of regional autonomy with Egypt and Israel sharing governance.
The Golan Heights. The 4,000 Druze inhabitants of the Golan ''have always been loyal to Israel,'' Mr. Elpelleg says. Many Druze serve in the Israeli Army. Hence, when Israel virtually annexed the Golan Heights last December, Arab specialists felt the Druze would loudly protest - but quietly be pleased with--the new arrangement.
But since annexation, the Druze have conducted an extended general strike and have been placed under strict Israeli curfew. Israeli officials say that during the curfew more than 3,000 Israeli identity cards have been passed out to Golan Druze. Despite the protests, Israel is considered virtually certain to hold onto the Golan. The Israelis see it as a vital military possession, and their goal is to integrate it into greater Israel.
The West Bank. Under the current Israeli government, the West Bank seems headed inexorably toward annexation by Israel. The Israeli government is currently implementing a policy aimed at controlling West Bank institutions (municipalities, universities, and so forth) and cultivating good relations with as many Palestinians as it can.
The policy is highly unpopular with West Bank Palestinians, and protests have frequently turned violent. But it seems to have considerable backing among Israelis. Israeli officials know, however, that giving citizenship rights to newly annexed Palestinians could eventually make the Jews a minority in their own country. Several officials hint that by putting sustained pressure on Palestinians they hope to stimulate emigration. One Israeli cited statistics showing a fractional drop in the West Bank Palestinian population last year as a sign this policy is already taking effect.