The Soviet Union is telling its people that the United States plans to blockade the Persian Gulf against Iran. Western sources here say the Soviets would try to exploit such a move in at least two ways:
1. By intensifying their propaganda barrage against the US, calling a blockade more evidence of US blackmail and pressure.
2. By offering the Iranians the chance of breaking the blockade by using overland trade routes to the north across Soviet territory.
Already the Soviets are advertising a "reliable and beneficial" container land-bridge service across the Caucasus and Siberia, linking Iranian cities to nine ports in Japan as well as to Manila, Hong Kong, and Bangkok via the Far EAst container port of Vostochny, which adjoins Vladivostok.
A Soviet correspondent also has described "heavy refrigerator trucks" carrying butter, cheese, baby food, construction materials, chemicals, paper, and other goods from West Germany, France, Britain, Belgium, Denmark, and other European countries to Iran across the Astara River on the Iran-Soviet Azerbaijan border.
Western sources see these moves as a logical Soviet response to a blockade. They don't see Moscow resorting to military means to help Tehran.
A "land bridge" would be more limited than sea lanes blocked by the US, but the Soviets would see it as a desirable political move to try to convince Ayatollah Ruhollah Jhomeini and whoever follows him that the Soviets are reliable trade partners.
The official news agency Tass has quoted the Iranian ambassador to Moscow as saying "good neighborly" relations still exist between Moscow and Tehran, despite differences on trade and politics.
Iran has canceled plans for a second natural gas pipeline to the southern Soviet Union, and the two sides have argued over prices to be charged for Iranian natural gas sent through an existing line.
The weekly Literary Gazette, aimed at intellectual readers, carried a report April 16 from New York saying "it had become known" that Washington was planning five steps against Iran.
First, a naval blockade of the Gulf. Second, mining ports in the northeast of the Gulf. Third, bombing Iranian cities. Fourth, invading southern Iran. Fifth, overthrowing the Ayatollah.
Pravda April 16 denied any Soviet military buildup north of Iran, as indicated by White House national security aide Zbigniew Brzezinski.
The Siberian land-bridge route to the Far East was advertised in the weekly Moscow News April 13. A Novosti correspondent, Igor Troyanovsky, described the refrigerated trucks in the same edition.
Meanwhile, Western sources here see the Soviets still caught in a dilemma as it views the chaos and confrontation in Iran.
On the one hand, Moscow welcomes the clash with the US. It thinks it shows President Carter as a weak leader. It weakens the US strategic position near vital oil lanes. It tends to divert attention from Soviet troops next door in Afghanistan.
A steady propaganda campaign here belabors Mr. Carter as a tyrant bent on humiliating and blackmailing a helpless Iran.
The Soviets now call Iranian demands that the Shah be returned as "legitimate." Iran, Moscow says, has offered a constructive solution, but the US has only itself to blame for rejecting Iranian terms.
Once the Soviet press deplored the seizure of the US Embassy and the holding of the hostages. But since Soviet troops went into Afghanistan the tone has changed. With detente in tatters, the Soviets don't make any gestures to American public opinion.They hardly mention the hostages or the violation of immunity.
The Soviet effort is to play up to the Ayatollah, trying to position the Soviets and the Iranian Tudeh (Communist) Party to take advantage of a post-Ayatollah era.
Yet, despite these pluses. Moscow finds the Iranian situation troubling to say the least.
The Ayatollah is fiercely anti-Soviet and anticommunist (though his words on the subject are censored from the Soviet press). When President Bani-Sadr looked like helping the US on the hostages, the Soviet press criticized him as well.
The present is unsable, the future uncertain -- and the Soviets don't like it. "The Kremlin is playing by ear now," says one Western source. "It lacks a discernible grand strategy."
The Soviets prefer stability, even if it depends on a monarch like the Shah, with whom Moscow did business for two decades.
Nor do the Soviets like the US naval buildup around the Gulf. They criticize it at every opportunity.