London, England, and Cambridge, Mass. — Middle Eastern nations, including Israel and to a lesser extent Egypt, are arming themselves today at a rate never registered before.
In 1979, when President Anwar Sadat and Prime Minister Menachem Begin signed the historic Egypt-Israel peace treaty, many in the West hoped that decades of Mideast strife were coming to an end. President Carter said he hoped the treaty would lead to ''permanent peace in the Mideast.''
These euphoric hopes appear to be fading. What is needed is a clear perspective on the outlook for the region and its evolving balance of power through the 1980s.
The last Arab-Israeli war was fought in 1973. The most striking development since then, experts agree, has been the effective removal of Egypt from a potential Arab war coalition. That remains, at least thus far, the most solid result of the 1979 treaty.
Without the leadership previously provided by densely peopled and culturally homogenous Egypt, the other Arab ''confrontation states'' remain weak, divided, and increasingly unstable.
Much of the high-tech weaponry the oil exporters among them have acquired remains far from operational. Some confrontation states are now committing more troops to quelling dissent at home than to manning the front line with Israel. Thousands of Syrian troops are tied up in Lebanon, their Iraqi counterparts bogged down fighting Iran in the Gulf war.
''Present-day Israel,'' sums up Prof. Nadav Safran of Harvard University, ''enjoys overwhelming military superiority over the Arabs.''
Born in Egypt, Dr. Safran is reputed to have once served as an informal adviser to former Israeli Prime Minister Golda Meir. He remains in close touch with Israeli affairs, while his professional commitment now is to studying Arab developments. His views are thus regarded as well informed on both sides of the divide.
If a new Arab-Israeli war were fought ''tomorrow,'' in Dr. Safran's view, the greatest potential Arab war coalition the most cautious of Israeli commanders could expect to face would be constituted roughly as follows:
* Syria could commit between 70 and 80 percent of its armed forces (the rest being needed to ensure internal stability).
* Jordan could contribute a similar proportion.
* Iraq could send ''around one division of ground forces and most of its air power.''
* The Saudis could send in up to two armored motorized brigades and about half of their operational air power. Only if hostilities are prolonged could further reinforcements join the Arab side from North Africa and elsewhere.
Working to Dr. Safran's guidelines, and taking the latest figures from the highly regarded International Institute of Strategic Studies (IISS) in London, the lineup on both sides in the first days of the war would thus be:
Israel 'Arab war coalition' Total armed forces 400,000 242,000 Medium tanks 3,500 3,612 Combat aircraft 602 624
Dr. Safran notes that in addition to its force superiority, Israel also possesses the following non-numerical advantages over an Arab coalition: the proven qualitative superiority of Israeli forces; short, efficient internal lines of communication facing outward; and a single political center making decisions of war and peace.
Small wonder that the information officer of the IISS in London, Maj. Robert Elliot, a Canadian, concludes that ''Israel could gain a clear military advantage over the Arabs at the present.''
The experts agree, as well, that the military balance is only part of the story. ''In pressing home its military advantage against the Arabs, Israel might lose much of its political advantage with the West,'' warns Major Elliot, a veteran of Mideastern peacekeeping tours.
Dr. Safran considers that Israel would need a quick and decisive win over the Arabs so as to knock out their capabilities before international political factors - which he sees as having swung against Israel since 1973 - have a chance to come into play.
''Israel must achieve its objectives within a short period of time - let us say 48 or 72 hours,'' he said.
After that, the Soviets could start resupplying Syria, while the United States might be inhibited from doing the same for Israel by its growing relationship with Saudi Arabia. And whereas the Soviets might veto any Security Council resolution apparently in Israel's interest, the US might be less eager to veto any cease-fire favoring the Arabs.
''The Arab coalition thus has an interest in a war of attrition,'' said Dr. Safran. ''Israel's interest is in a quick blitz war. If the Arabs can defend key targets through good air defense, they can improve their chances of stretching out the war. Israel must concentrate on penetrating those defenses.''
Both Israel and Syria have made enormous efforts in these respective directions since 1973. But as far as Major Elliot is concerned, ''the Syrian air defenses have not been properly tested yet.'' So the outcome is still not fully predictable.
Other major factors would also have to be taken into consideration in the event of a new Arab-Israeli war. Foremost among these are:
Soviet response. The Soviet Union has been linked to Syria in a formal Treaty of Friendship and Cooperation since October 1980. To what extent would it intervene to save President Hafez Assad's government there if the Israelis appeared about to defeat him in battle?
One veteran Arab analyst of strategic affairs, who prefers to remain anonymous, commented that any forthcoming war between Israel and Syria would provide a real test of Syrian-Soviet relations. ''Whether the Soviets would get directly involved or not remains to be seen,'' he says. ''But it is quite logical that the Syrians would try to get them in.''
Major Elliot of the IISS doubts that the Soviets would respond. ''What could they do? Transport troops to Syria? It's a long way,'' he said. ''Would they put the whole process of entente at risk for the Syrians? I don't think so.''
Saudi response. Public pronouncements by Saudi leaders over the years since the 1973-74 oil embargo have increasingly sought to divorce the whole question of oil supplies from the Arab-Israeli dispute. They repeatedly tell their more impatient Arab brethren that the oil weapon, which includes huge financial holdings in the West, has become two-edged and cannot lightly be brought into play.
But serious doubts remain over whether oil can ever be totally divorced from politics in the coming decades of Western dependence on Mideastern supplies. ''On the contrary, the two have become inextricably linked,'' Dr. Safran stated flatly. ''And in a war situation the pressures on Saudi Arabia to use the oil weapon in some way or another would be enormous - regardless of what the Saudis might say now.''
Dr. Safran and the Arab analyst agreed that the mere fact that the Saudis have already once used the oil weapon would greatly increase these pressures.
This would, in the view of most informed analysts, be the major contribution the kingdom could make to any future Arab war scenario. The Saudis have acquired huge and ultramodern arsenals - ''but much of the Saudi inventory remains just that,'' said Dr. Safran. ''Little of it is immediately operational.''
The Arab analyst concurred in the conclusion that, regardless of the airborne warning and control system (AWACS) surveillance planes and other arms purchases, Saudi Arabia remains far from constituting a significant military power.
He argued: ''The Saudi population is relatively small, with much of it remaining outside the modern social structure the Saudis are still trying to build. Most sensitive sections of the Saudi Army such as the Air Force are actually, if not officially, under American command. And whatever sophisticated hardware the Saudis might own there are no signs at all that it has been absorbed yet.
''Egyptian response. The foregoing conclusion that Israel remains militarily stronger than the Arabs was all predicated on Egypt's continuing absence from the ranks of Arab fighters. But right near the top of the Israelis' repeated ''What if?'' questioning, lies the fear that this situation might not last for long.
The anonymous Arab analyst, who has a long acquaintance with Egypt's highly developed sociopolitical structures, argues bluntly that ''I cannot see Egypt stable without joining any present or future Arab-Israeli war that could break out. This instability might not be decisive during such a war,'' he says. ''But it would be decisive afterward.''
This analyst does not think Egypt's present absence from Arab ranks can persist for a long time.''
The peace treaty,'' he argues soberly, ''gave Israel continuing military rights on and around Sinai. I don't think it will be long before the Egyptian military sees the humiliation of this. At the same time, Israel's high-handed military policy toward Lebanon, Iraq, the West Bank, and Gaza are not passing unnoticed by Egyptians in general, and the Egpytian military in particular.''
Harvard's Dr. Safran thinks it will still take some time before the Egyptian military would consider joining a war against Israel. Right now, he says, the military is in a tricky situation, still only halfway through the transition from a basically East-bloc armory to a basically American armory.
''It will take, say, three to five years before they are once again homogenized and battle ready,'' Dr. Safran said. ''During that period, the Egyptians might use the excuse of the peace treaty not to engage in an Arab war coalition.''
And even after that period, he argues, ''there are still apt to be political constraints. Egypt is not likely to go to war against Israel if the US is on good terms with Israel. . . . Though if US-Israeli relations are strained, Egypt might find it useful to break its relations with Israel, and Israel must take that into account.''
But even if a radical nationalist regime opposed to the peace treaty did come to power in Egypt at some stage and swing back toward the Soviets, it would still take time to build up a viable Soviet-armed force to confront Israel, Dr. Safran feels.''It would take time to rebuild Egypt's armed forces again, for the third time in their modern history, on the basis of a completely new weapons inventory.
It would take time to reestablish relations with an Arab world still dominated by conservative Saudi Arabia.''His conclusion? ''I don't see Egypt ready to fight Israel in the '80s.''