Behind the one-way glass of an unmarked Cairo office building is a brave new world of clean marble floors, push-button telephones, closed circuit television and uniformed guards carrying chrome-plated revolvers.

The air-conditioned calm and the atmosphere of efficiency, so rare in Cairo's turbulent shabbiness, mark the place as special, but nothing visible gives any clue as to what goes on there.

It is the headquarters of the Arab Organization for Industrialization, a unique consortium of four Arab nations whose purpose is to put the Arabs into the business of making and selling sophisticated instruments of war.

Since its founding three years ago by Egypt, Saudi Arabia, Qatar and the United Arab Emirates, the organization has attracted little attention. It is run by men who shun publicity and apparently has not actually produced any weapons.

Informed military sources say, however, that it is nearing the point where it will begin manufacturing missiles and helicopters, which will be the first time major weapons systems have been built in the Arab world rather than being imported from the United States, Western Europe or the Soviet bloc.

Arab dependence on imported weapons and technology will remain high for years to come, military experts say, and nothing in the new organization's program would alter the military balance between the Arabs and Israel, which already produces its own combat jets.

In the long run, however, the Arab arms program could increase the overall level of Arab military technology and move the Arabs toward selfsufficiency in some types of weapons.

Sheikh Khalifa Bin Zayed, deputy commander of the armed forces of the United Arab Emirates, said last winter the development of an Arab arms industry had become "a vital necessity for the peoples of the Arab nation to promote their own forces and break the weapons monopoly" of the advanced countries.

The Arab arms organizations, which was endowed with more than $1 billion in an effort to marry oil money to Egyptian skilled manpower, is the first serious Arab move toward the goals expressed by Sheikh Khalifa. Assessments of its prospects for success vary.

"It's vastly undercapitalized and only a vague threat to the Israelis in the sense of telling them, "we are building the mighty AOL," one Western expert here said. "The Egyptians can handle the small stuff but anything involving real technology is nonsense. Build their own planes? No way. And even tanks would take years."

Another official familiar with the organization, however, said that the three years since its founding have been well spent in deciding which weapons systems to build, in acquiring plants and in training personnel. "Considering they started from scratch, without even an office, they have done a lot. They have some very bright people working out there," he said.

The chairman of AOI is Ashraf Marwan, who is a son-in-law of the late Egyptian President Gamal Abdel Nasser, and has a reputation as a wheeler-dealer. He did not respond to repeated requests for an interview.

Marwan reports to a four-member board of directors consisting of the defense ministers of the member countries. They have said little beyond official announcements about the organization, but reliable reports here and in Europe give this picture of AOI progress:

The organization signed secret protocols with France and Britain early this year under which AOI and industrial firms from those countries will undertake coproduction, in Egypt and Saudi Arabia, of some military equipment.

One deal calls for construction of 50 Lynx helicopters in partnership with Westland of Britain.The first 20 of these are to be built in Britain, the rest in the Cairo industrial suburb of Helwan under British supervision.

Another contract provides for coproduction in Egypt of the British-designed "Swingfire" antitank missile.

An arrangement with American Motors calls for the assembly of up to 12,000 Jeeps a year at a factory in Egypt. This deal, the only one with an American supplier, is officially described a sone for "nonlethal" equipment, but the Swingfire missiles can be mounted on vehicles, military experts said.

Under contracts with the French firms of Thomson-CcSsFf and Matra, the Arab organization and the French will manufacture electronic equipment and surface-to-surface and air-to-air missiles at plants in a new military city under development near Riyadh, Saudi Arabia.

Under all these contracts, military sources say, AOI is to form partnerships with the supplier, who is to deliver technical assistance and training as well as equipment. Over the course of years, it is envisioned that the non-Arab personnel needed to supervise three operations would be phased out as local workers are trained.

The organization, however, has not succeeded in its efforts at making a similar deals that would lead to any aircraft production. Discussions about coproduction of France's supersonic Mirage F-1 ended without agreement, and AOI then sought the France-West German Alpha jet, a much less formidable aircraft intended largely for training, according to authoritative sources.

That deal has not been concluded apparently because of West German reservations about the corporate structure of AOI and about who the buyers of these weapons would be.

Analysts here say it is the organization unique corporate structure, as much as any technological or financial problem, that has blocked some of the arrangements it has sought to make. The organization is neither fish nor fowl, they say neither a private corporation nor an instrument of a single government and this has inspired some reluctance in Western governments accustomed to making arms deals on a bilateral basis.

Sources familiar with the organizations charter say that AOI intends to sell its weapons not just to its four Arab partners but to other customers as well.

It is not clear whether the four participating governments have committed themselves to buy what AOI produces. If they have not, it is questionable whether an American or European firm would find it profitable to engage in joint-venture partnerships to build weapons for an uncertain market.

But even more troubling to Western governments that have negotiated with the organization informed sources say, is the question of who besides the four founding companies might buy the weapons.

A country that might be happy to supply arms to Saudi Arabia or the Arab Emirate might be less comfortable if it wound up helping to provide missiles for Iraq or Algeria, diplomatic observers point out.

Although the participants in the contracts already signed have refused to give details, it is understood that both Britain and France extracted commiments that give them, some control over the marketing of the helicopters and missiles to be produced.