There was a hollow ring to the rhetoric when representatives of the Arab countries gathered in Tunis last month for an Arab League meeting.

The ritual incantations about solidarity of the "Arab Nation" seemed even less convincing than usual at a time when virtually all the Arab states of North Africa and the Middle East are facing conflict with their neighbors or turmoil at home or both.

The fact that the meeting was in Tunis instead of Cairo, which has been the seat of the Arab League for 34 years, emphasized the deepest split of all, the break with Egypt.

Unwilling or afraid to follow Anwar Sadat down his path to a negotiated peace, and unable to head him off, the Arabs achieved a measure of unity in their opposition to what he did. But now the peace treaty, the revolution in Iran, religious conflict, territorial claims and domestic power struggles have the Arab world in turmoil and there is every sign that they will continue to suffer violence, tension and upheaval for years to come.

Trouble is brewing from Morocco to Iraq. Some of the conflicts will blow over, some will simmer along without real violence, but others, it seems certains, will explode into the border wars and coups d'etat that have marked so much of modern Arab history. When they do, they will attract the interest and perhaps the involvement of the industrial powers, because however trivial or parochial the causes of intra-Arab conflict may appear, the region's strategic location and oil resources give this area a burden of world importance that the countries are ill prepared to bear.

Most of the Arab states have been free of colonial domination long enough to develop their own national interests - political, economic and territorial - that conflict with those of their neighbors. These issues override the solidarity that bound them in their struggles against the British, French, Italians and Turks.

Few of these states, however, have succeeded in developing political systems that function independently of the individual or fraction giving the orders at the moment. Except for Saudi Arabia, Kuwait, Qatar and Bahrain, there is hardly an Arab country in which it is possible to say with certainty what system of government and international orientation would emerge if the present ruler were to die.

These built-in tensions have been exacerbated by the Iranian revolution, which sent shock waves throughout the rich but defenseless sheikdoms of the Gulf, by oil wealth, which has catapulted primitive societies into the computer age overnight and by the Egyptian-Israeli peace treaty, which left Syria, Jordan and the Palestinians feeling exposed and abandoned on Israel's eastern flank.

Egypt's president, Anwar Sadat, says that the other Arabs need to perpetuate the conflict with Israel to hold themselves together and to rationalize their repressive domestic policies. But without Egypt, that conflict is more perilous for them.

Syria's challenge of Israel in last week's aerial dogfight over Lebanon was politically useful to the struggling regime in Damascus, but it showed again that while the Arab opponents of the peace treaty may be able to boycott Egypt, they cannot lay a glove on the Israelis and they have no effective program for regaining their lost territories.

Some senior Arab officials believe there will eventually be a reconciliation between Egypt and the other Arabs. They see future in which Sadat, having regained all of the Sinai, will acknowledge the failure of his attempt to secure the rights of the Palestinians and will join Syria and Jordan in a new diplomatic campaign against Israel. The Israelis, however, are not obliged to complete their Sinai pullout for three years and Sadat is not likely to do anything in the meantime to give them a pretext for halting it.

That Egyptian officials say, is why Cairo, though verbally protesting Israel's actions in Lebanon and the West Bank, is pressing ahead with peace. This, in turn, increases the anger of the other Arabs.

Arabs, even Egyptians, still argue that there is validity to the concept of one "Arab Nation," a people of mutual culture and interests who in times of crisis rise above their fratricidal quarrels.

"Of course if you have 22 Arab countries you have 22 foreign policies," a senior Arab diplomat said recently. "It's like a tree with 22 branches, or a family with 22 quarreling brothers. The quarrels are bitter, but it's still a family."

Nevertheless, the Arab countries pull apart as often as they pull together, particularly in the absence of any charismatic leader who has popular appeal across national lines. The deaths of Egypt's Gamal Adbel Nasser in 1970 and Saudi Arabia's King Faisal in 1975 removed the two men who had the talent and the popular appeal to influence the entire "Arab Nation," and they have not been replaced.

The causes of the conflicts within and between the Arab countries are as varied as the countries themselves, but many of them are fundamental and cannot be prepared over or settled by rhetorical appeals to shopworn concepts of unity or revolutionary soldiarity.

In North Africa, Algeria and Morocco are again on the brink of war in their struggle over Western Sahara. Algeria achieved an orderly transition of power after death last year of its president, Houari Boumediene, but reports are beginning to emerge of conflicts between the new president, Benjedid Chadli, and his rivals.

Tunisia, the Arab League's new home, has been politically paralyzed for years by the incapacity of President Habib Bourguiba. The country's fractious youth and militant labor unions are a potential source of upheaval when the 75-year-old "supreme combatant" finally dies.

Libya - now the "Socialist People's Libyan Arab Jamahiriyah" by order of Col. Muammar Qadaffi - is in the grip of his bizarre economic and political program for reforming the society. It has brought material wealth and greatly improved living standards to the Libyans, but has also brought chaos to the government and economic systems.

Qadaffi himself, always mercurial and mistrusted by his fellow Arabs because he is a zealot, is reported in the Arab press to be having trouble with his armed forces because of their humiliation in the Uganda war.

On the other side of Egypt, the likelihood of trouble and upheaval is even greater. The intractable mess in Lebanon sputters on, making bloodshed routine. It is difficult to envision an end to it until the Palestinian question is resolved, and that will not be soon, regardless of what happens in the negotiations between Egypt and Israel.

Syria seized the opportunity of Egypt's defection from the Arab ranks to mend its fences with archrival Iraq, but President Hafez Assad has enough other troubles to keep him busy.

As the massacre of cadets at the military academy in Aleppo revealed once again, Syria is a violent society driven by religious and regional strife, and traditionally difficult to govern. The main reason Assad keeps his army in Lebanon is to prevent that country from being formally partitioned along religious lines, which might set a precedent for his own.

In the rest of the Arab world, the story of rivalry, conflict and potential upheaval is the same. Iraq is again at odds with non-Araq Iran. Kuwait is always conscious of the threat from the Palestinians who make up half is population.

The United Arab Emirates, and even Saudi Arabai, are rich, weak countries increasingly dependent on foreign labor and looking for ways to reinforce their security now that Iran is no longer the "policeman of the Gulf."

The insurgence in Oman's Dhofar Province appears to have flared up again, with claims of military victories coming from Marxist revolutionaries based in South Yeman. South Yeman and North Yemen have not resolved the disputes that led to their border war earlier this year.

Many Arabs blame outside forces - Israel, the big power, the legacy of colonialist rule - for the disharmony in their ranks. They are often right, but just as often they are suffering from self-inflicted wounds.In a world where beligerent oratory, half-baked slogans and theatrical gestures often provide the building blocks of statecraft, the bleeding from those wounds is likely to go on for some time. CAPTION: Picture 1, GAMAL ABDEL NASSER . . . influenced all Arabs; Picture 2, KING FAISAL . . . was a unifying force