The recent arrival from Afghanistan settled himself against a cushion and began, "Today I will tell you a tale." Indeed he did, spinning during the next hour what appeared to be a highly fanciful account of his journey by road through the rebel-held areas of Afghanistan.

He was not deliberately trying to mislead, but rather was following a great Afghan tradition of storytelling. T was right out of "bazaar of storytellers" in the Khyber Pass city of Peshawar, Pakistan, where for centuries travelers have recounted exaggerated tales of their adventures crossing Afghanistan by caravan.

Nowadays, the stories related by travelers from Afghanistan have become part of the news reporting of the Soviet occupation of Afghanistan -- a country which for the most part is off limits to Western correspondents.

I was able to obtain a visa for a six-day stay in Kabul earlier this month when officials at the airport neglected to ask if I were a journalist.

Since then, the Soviet-installed Afghan government has pulled the curtain tighter around Kabul by stopping the practice of giving out visas at the airport.

Thus, reporting the major East-West confrontation under way in the world today has become a second- or third-hand affair -- a combination of seekingg out diplomatic sources with information from Kabul, gleaming tidbits from Radio Afghanistan and trying to separate fact from exaggeration in travelers' reports.

Some of those reports are suprisingly good, coming as they do from untrained observers. They have contributed to news breaks that have been subsequently borne out by events and other observations. But other reports are alarmingly bad, contributing only to the confusion.

For reporters based here, it is an exceedingly frustrating occupation. It is just as bad in Peshawar, the headquarters of at least six Afghan rebel groups that issue press releases with high exaggerated accounts of their battlefield successes against the Soviets.

But even in Kabul, finding out what is really going on is a chancy affair.

It is impossible for a Westerner to venture far out of the Afghan capital these days, although in January, soon after the Soviet invasion, some correspondents made highly hazardous trips by road to some other cities.

But now even the key highway heading east from Kabul through Jalalabad and the Khber Pass to Peshawar is often closed. The Pakistani bus on that route, nicknamed "The Silver Bullet," is no longer in service, although an Afghan bus makes the trip when the road is not closed by rebel attacks.

The Kabul rumor mill, however, is going full blast, and it is often those rumors, relayed here by travelers or diplomats, that lead to erroneous stories going around the world.

It was, for instance, one Afghan traveler arriving here on a flight from Kabul in June who spurred the false reports -- passed on by all the wire services -- that 20,000 rebels were surrounding Kabul and were ready to attack it in what was to be a decisive battle for control of the Afghan capital.

As far as can be determined, no 20,000-unit rebel force ever massed outside Kabul. Indeed, a story, probably apocryphal, circulating here says that Soviet generals heard the report of the rebel offensive over the British Broadcasting Corp. and rushed tanks and helicopters out to repulse it. That, of course, sparked diplomatic reports that led to a second round of stories of the Soviets moving to defend Kabul from rebel attacks.

The original report of the rebels massing around Kabul came from a short-lived pool arrangement set up by foreign correspondents here in which one reporter would meet incoming planes from Kabul to get the travelers' reports and pass them on to everyone else.

The pool was soon disbanded, largely because many of the correspondents based here realized it placed everybody at the mercy of the least reliable reporter on the day he was meeting the plane.

Even the best sourced reports of Afghan fighting produced errors. In the Pakistani capital of Islamabad in January, a reliable Western European diplomat told an inquiring reporter that his country's embassy in Kabul was reporting heavy fighting around the airports, with Soviet Mig fighters seen striking around the city.

In an on-the-record interview later that day, Pakistan President Mohammed Zia ul-Haq confirmed and elaborated on that report on the basis of information he said he had received.

The Washington Post, acting on two different sources, incuding one who allowed his name to be attached to the report, carried a front-page story on the fighting.

According to correspondents who were in Kabul in January soon after the Soviet invasion, some of the most hysterical and unreliable reports on activities within Afghanistan came from daily briefings given by American diplomats. Many of these diplomats are no longer based in Kabul, and American diplomatic reports have gained greater credibility recently.

Still, there is a tendency among some diplomats to exaggerate. Two diplomats from a nonaligned nation are famous for their vivid, often contradictory, briefings, containing opinions and "information" they admit they never send back in dispatches to their governments.

There is also the case of a diplomat who talked about Soviet air and land attacks on 50 to 100 Afghan villages that caused "dozens of thousands" of casualties -- highly unlikely since most Afghan villages are a few, mud huts with populations in the hundreds.

When pressed, he admitted he had arrived at the casualty figure by estimates and extrapolations. In fact, he had just guessed, probably wrongly.

The best reports are those that have different sources arriving at the same conclusions.Stories late last month, for example, of massive Soviet air and land offensive in Wardak and Ghazni, tied to reports of an Afghan division mutiny, came from different diplomatic sources who often vary in their interpretations, of Afghan events.

Western reporters want to get into Kabul to try to report first hand what is going on there. The Foreign Correspondents Association of South Asia sent a cable Monday to Afghan President Babrak Karmal asking him to admit correspondents from noncommunist countries.

"Because we have been prevented from going to the scene," the cable read, "we have had to rely on reports from travelers, diplomats and Afghan expatriates about what is going on.

"We submit that the best way is for yo to admit journalists from established newspapers and news services without restrictions and allow them to fulfill their responsiblities freely."

One member of the association's board, Pravda correspondent Vanjamin A. Shurigin, opposed sending the cable. He said his organization has no trouble getting reporters into Afghanistan.