Iraq's revolutionary socialist regime eyes the chaos across the border in Ayatolllah Khomeini's Iran with bittersweet ambivalence, predicting the disintegration of its ancient enemy but fearing that might bring in the two superpowers to frustrate Iraqi ambitions for dominance in the Arab world.

Sharing Khomeini's enmity has not warmed officially frosty relations between Baghdad and Washington. Rather, two Iraqi officials suggest the Americans might have designed the hostage crisis as a pretext for bringing military force to the Persian Gulf. That, these officials believe, would open the doors to satisfaction of Russia's timeless longing for Iran. Furthermore, Iraqis see post-Khomeini Iranian regimes controlled by Washington or, much more likely, Moscow.

Despite Moscow's role as Iraq's ally and arms supplier, Baghdad is worried most by the purposeful men in the Kremlin, not by Jimmy Carter. While U.S.-Iraqi relations cannot warm without unexpected cooling by Washington toward Israel, there is concern here, as in the conservative states of the Arabian peninsula, about the Russian bear's oil hunger in the 1980s.

Iraqi leaders do not hedge in condemning the Iraniqn seizure of the U.S. Embassy as being against the law of Islam. Nor do they flinch at forecasting Iran's disintegration as a multi-nationality state. Tariq Aziz, a deputy prime minister and President Sadam Hussein's closest adviser, has said bluntly: "The shah didn't solve the problem of national minorities. Khomeini says Islam is the way. But that won't work, either."

Accordingly, he sees Baluchistan, Khuzestan, perhaps Azerbaijan, and certainly Kurdistan splitting from Iran's ruling Persian minority, contending the Kurds of northern Iran now will settle for nothing less than pure independence.

As we reported earlier, following firsthand observation, the supposed Iraqi invasion of Iranian Khuzestan was the invention of Radio Tehran. It is impossible to say whether there is any more truth to Iranian complaints that Baghdad is fomenting Kurdish rebellion. Iraq, denies reports, believed authenitic by both Western and communist diplomats here, that it supplies arms sent to Iranian Kurds.

Whatever the truth, the dismantling of Iran is not Iraqi policy. In a recent confidential conversation, Hussein (who privately calls Khomeini a madman) declared Iran must not be permitted to fall apart. That explains government declarations disavowing belligerence toward Iran.

One Iraqi general staff officer said recent maneuvers were geared not to Iran, but to foreign forces in the Arabian (Persian) Gulf -- presumably both Soviet warships and the USS Kitty Hawk. "I think the Iraqis would have much more sympathy for the Americans in Tehran," one Western diplomat suggested, "if they were absolutely sure you would not intervene militarily." Sure or not, Iraqi leaders would not stop worrying about what they fear will follow Khomeini quite soon: possibly a military regime linked to Washington; probably a communist regime linked to Moscow.

Concern here over a communist Iran reflects less than comradely Soviet-Iraqi relations. A Soviet air marshal who just visited Baghdad was not given the treatment accorded Third World luminaries. When he placed flowers on the unknown soldiers' tomb, no senior Iraqi official accompanied him.

The regime regards the suppressed Iraq Communist Party as linked through fraternal communist parties to Eastern European states -- including the Soviet Union. Thus, Iraq blamed the Bulgarian government when an Iraq student in Bulgaria was killed in turmoil between Iraqi students loyal to Baghdad and exiled Iraqi communists.

While police here kept demonstrators far from the U.S. mission after the Camp David signing, authorities permitted protesting throngs to press against the Bulgarian Embassy's gates, after Iraq's ambassador and all its students were brought home from Sofia. Bulgaria sent a deputy prime minister to Baghdad with formal apologies -- still not satisfying Iraq. Bulgarian kowtowing was obviously on orders from Moscow, which wants to preserve this Mideast foothold, shaky though it is.

But Soviet satellite kowtowing will not end dismay here over Soviet airborne troops fighting the Moslem insurrection in nearby Afghanistan. "We are concerned by political or military action in the region by any major power," Aziz told us. As for the Russians as a prospective oil importer posing an additional threat, he added: "We in the Baathist Socialist Party believe all big powers are expansionist in nature."

Iraq wants to make its nonalignment more than a catch phrase, mainly through increased American business contacts. Hussein personally noted the exclusion of U.S. exhibits from October's Baghdad International Fair and made it clear there had better be some there next year.

But there is no pressing desire to resume formal diplomatic relations, which were broken in 1967. Indeed, U.S. sponsorship of the Camp David accords has enabled Iraq, using oil money and Baathist ideology, to envision political dominion of the Persian Gulf.