The mounting war of words and deeds between Iran and Iraq threatens to: * Open up dramatically and violently one of the great ethnic and cultural divides on the earth's surface -- that between Arabs and Persians. Along that divide, the tide went in favor of the Arabs back in A.D. 637, with Arab victory at the battle of Qaddisiyah, on one of the canals of the River Euphrates.
* Revive the struggle among the three major states on the Gulf to dominate it , temporarily decided in favor of Iran following the British withdrawal from east of Suez in 1971. (The other two contestants are Iraq and Saudi Arabia.)
Iraqi strong man and President Saddam Hussein is continuing his summary expulsion from Iraq of thousands of Iranians or Iraqis of Iranian origin. His aim is not merely to hit back at Ayatollah Ruhollah Khomeini and other Iranian leaders for their campaign against him. He also wants to remove from Iraq those whom he identifies as troublemakers or pro-Khomeini elements in Iraq's big Shia Muslim community.
At least 50 percent of Iraq's Arab population is Shia Muslim. But Shia Muslims, who tend to be poorer as a whole than Sunni Muslims, traditionally have been excluded from power ever since Iraq came into being as an independent state after World War I. President Saddam is a Sunni.
This Shia Muslim component in the Iraqi population, resentful of Sunni domination, is understandably vulnerable to revolutionary calls in the name of Shia islam from that dominating Shia Muslim patriarch Ayatollah Khomeini across the border in Iran.
This is all the more so since the Ayatollah spent over a decade of his 14 -year exile from Iran in Iraq -- at Najaf, together with Karbala, also in Iraq, the two holiest sites in Shia Islam.
Iraqi President Saddam and the Ayatollah have been trading blows of one kind or another for over a year now. On April 1 of this year one of Mr. Saddam's close associates, Vice-Premier Tariq Aziz, was wounded when a grenade was thrown at him at a university gathering in Baghdad.It was seen as an assassination attempt. The Grenade-thrower was promptly set upon and killed; but the Iraqi authorities had no hesitation in blaming Iran.
With that remarkable memory for history that one finds throughout the Middle East, Mr. Saddam described the attack on Mr. Aziz as a "perfidious act by cowards trying to avenge Qaddisiyah."
That battle more than 1,300 years ago brought to an end the glorious empire of the PErsian Sassanids -- and to the flourishing of their Zoroastrian religion. Impelled by the revelation that came to the Prophet Muhammad, the Arabs were sweeping all before them and converting all in their path to the new monotheistic religion of Islam.
It was a bitter experience for the long-triumphant Persians, a people of Indo-European roots, contemptuous of the ethnically different Semitic Arabs who had appeared as warring tribesmen from the deserts away to the southwest. But the Persians even then managed to preserve the uniqueness that is their pride: They opted out of the Arab-dominated Sunni Muslim mainstream and chose for themselves the distinctive heterodox Shia branch of Islam instead.
In the revival of this ancient hostility between Arabs and Persians, now erupting as a dispute between modern Iraq and modern Iran, each side holds hostages of the other. Iraq is vulnerable because of its potentially dissident Shia population. But Iran is, in turn, vulnerable because the indigenous population of its oil-rich province of Khuzestan (known to Arabs always as Arabistan) is Arab. Further, both countries have sizable Kurdish minorities, which each can use against the other.
The Kurds are Sunni Muslims but have no great love for Arabs, even Sunni Arabs. But antipathy toward Arabs does not make the Kurds in Iran automatically pro-Iranian or pro-Persian, because the Persians are of the Shia faith.
If Mr. Saddam is correct in saying Ayatollah Khomeini wants "to avenge Qaddisiyah," there is little doubt that the Iraqi leader wants to avenge a more recent defeat inflicted on Iraq -- albeit not in a clash of arms. That defeat came in the opening years of the 1970s when Iraq lost out to Iran as heir to Britain's role as dominant power in the Gulf (called "Persian" by the Iranians and "Arabian" by the Arabs).
Of the three potential heirs to this role, both the US and Britain saw the Shah of Iran as the best placed and equipped to be bequeathed the legacy. The Shah was only too willing -- and drove home to his neighbors his newly acquired position by seizing three small islands at the southern entrance to the Gulf that had belonged until then to Arab emirates on its western side.
Now, a decade later, with the Shah's power shattered and with Iran's once-superior armed forces in considerable disarray, Iraqi President Saddam has seized the moment to restate Iraq's claim, earlier brushed aside, to mastery of the Gulf.
The three islands are again central to the act. Mr. Hussein has laid claim to them -- a claim as fiercely rejected by Ayatollah Khomeini as the ousted Shah would have rejected it.
The Ayatollah and his fellow Persians are buttressed by memories of their great past. But Mr. Saddam feels buttressed by history, too: the Tigris and Euphrates valleys, which cut across Iraq, were one of the two great centers of Middle East civilization millennia ago.
The other, equally centered on rare water in the desert, was the Nile. Egypt's President Sadat has always known that.