The hottest political topic in Syria is the apparent souring of relations with Iran. Some signs of strain:
* Iranian tourists and religious speakers, who flock here by the hundreds, must now get permission from the Syrian government to visit the tomb of Zeinob, south of Damascus. Zeinob was the daughter of Islam's founder, Muhammad.
* In the western Syrian town of Zebdani, where local legend has it that Adam's tomb and Noah's ark rest, the famous ''youth camp'' that in 1982 became the largest base of operations for Iran's Revolutionary Guards now features only a limp Iranian flag and a handful of patrol guards.
Western diplomats once feared that Syria would become the major base for the Iranians to export their revolution to the Arab world. Now the camp's estimated 1,000 Revolutionary Guards are gone.
* The daily 4 to 6 p.m. lessons in Islamic teachings are closely monitored by Syrian officialdom.
The Syria-Iran alliance was always unnatural, since Persian Iran is the Islamic world's most Islamic state and Syria has the Arab world's most sophisticated secular government. And now Damascus appears to be growing anxious about its fanatic friends.
Last month Vice-President Rifaat Assad, the younger brother of the Syrian President, delivered a speech to the academicians' association here in which he made public his doubts about continued support for the Islamic Republic, despite Damascus's and Tehran's shared goal of toppling Iraqi President Saddam Hussein.
Indeed, guests who attended the talk said the younger Assad went further during the question period. He said that if Iran won the Gulf war against Iraq, he could foresee the day when Syria might have to confront militarily the Iranians or their Iraqi agents off the Syrian border.
Muhammad Hayder, the powerful chief of external relations in the ruling Baath Party, denied that there had been any change in relations. But, he said, ''This does not necessarily mean that if Iran makes a military thrust against any Arab territory for the purpose of expansion or annexation, our attitude will continue as it is now.''
For a Syrian official to go on the record on the subject is telling enough. And he added in an interview:
''Of course Iran wants neighboring Islamic countries. But if Iran wants to install a government with a 'misinterpreted' form of Islam, this will be a kind of colonialism we will have to face and counter. No one is allowed to impose his views on others.''
Western and Arab envoys who have been monitoring the unusual alliance - Syria is one of only two Arab nations to back Iran actively - cite four reasons for President Hafez Assad to back away from Tehran:
* Since Damascus began its peace initiative in Lebanon in February, Syria and Iran no longer share a common interest in destabilizing the Lebanese government.
But while Mr. Assad struggles to solidify the new Lebanese government, the Iranians and pro-Iranian groups in eastern Lebanon continue to propagate their fanatical brand of Islam with their proclaimed goal of establishing an Islamic republic in Lebanon.
This in turn has threatened the status of the moderate Shiite leader, Nabih Berri, a Syrian ally and member of the new Lebanese government. Indeed, he has been under such pressure that, as a condition for joining the Lebanese government, he asked the Syrians to ''remove'' the Iranian influence that has made deep inroads among Lebanese Shiites, insiders say.
About the same time, Zebdani was evacuated, although there are still Revolutionary Guards in Lebanon, military sources say.
* Economically, the Syrians are in a quandary because of the expansion of the Iran-Iraq war. Syria's chief financial backer, Saudi Arabia, is pitted against Iran, which provides Syria with oil at such a discount that virtually one-sixth of its supply is free.
At recent talks to renew the oil deal, friction developed. Syrian officials had to plead that their back debt for nonpayment for oil be converted into a soft loan with low-interest repayment over the next five years. The debt is reportedly as high as $400 million.
''A lot of bad blood was spilt on the table,'' one foreign envoy said.
But Iran eventually came to terms because it wants Syria to keep the Iraqi oil pipeline that crosses Syrian territory closed.
* The Assad regime has begun to envision the possibility of a fanatic government in Baghdad that might have designs on Syria, a nation whose Constitution mentions Islam only once. Although it desperately wants President Hussein ousted, Damascus has begun to fear the alternatives.
* The recent succession struggle in Syria brought the alliance with Iran into the public arena as various factions tried to rally support by condemning what has always been a largely unpopular relationship.
Diplomats say the average Syrian prefers to support an Arab regime, whatever the disagreements, over the ''arrogant'' Persians. This, in turn, has put additional pressure on Assad.
''Syria is not likely to break off relations in the near future,'' one envoy said, ''but you can now clearly see the distance Damascus is trying to maintain from Tehran.''