To get an idea of why, despite its economic insignificance and its remoteness, Afghanistan is really a vitally important little state, it is only necessary to drive three hours north of Kabul, and up to the world's highest road tunnel at the notorious Salang Pass.

At more than 11,000 feet it is still bitterly cold and the great cliffs of the Hindu Kush are swept with blizzards every day. Thanks to the two-mile tunnel driven through the mountains a decade ago, however, it is now comparatively simple to drive from Kabul up across the mountains and to the southern steppes of Central Asia, in a long, tiring day.

The Russians built the Salang Tunnel.It took them 10 years and it cost them about $600 million.Thousands of Afghan laborors keep the roadway from beaking up in the bitter frosts and the winding approach roads free of landslides.

Standing at the entrance to the tunnel and looking south toward the Kabul Valley or north towards Tashkent and Samarkand, it is natural to ask: Why should they spend $600 million on a little used roadway across the Hindu Kursh? Surely not just for the truck loads of raisins that toil up the pass each day?

Of course the answer is no. The Salang tunnel was built to enable Soviet convoys - military convoys in all probability - to cross from the cities and army bases of Uzbekhistan all the way over the Khyber and to Pakistan. Military men say it is possible to make the journey in a day - meaning that, if they chose, Soviet military commanders could have their tanks rumbling up to Pakistan's Northwest Frontier Province in virtually no time at all.

That they might ever do so is, under present circumstances, almost inconceivable. Yet, it is a fact that Afghanistan's relations with Moscow for the last five years have been good - and now, with Kabul under the leadership of Nur Mohammed Taraki, are likely to get much better. This is at least allows the scenario to be considered.

The Salang tunnel symbolizes Afghanistan's importance as a classic buffer state, nestling contentendly between the proxies of the rival powers, a land to be driven across, to be flown across (as the Soviets did recently, on their way to help the Ethiopians), even to be gently annexed.

After three wars with the British, every Afghan knows why his country once was important in the Tussles between the old empires. After the coup of 10 days ago, every thinking Aghan knows why, once again, he is important in tussles between the descendants of those empires.

This brings up the question of the credentials of Taraki's new government, now a week old, relatively well-organized, and recognized by all the powers and neighbors that matter. Will Afghanistan now be reduced to little more than a roadway cafe on the invasion routes south for Russia, or is it true to say, as Taraki insists, that "We are a satellite of no one. This revolution was accomplished on the Afghan model, one which is unique, and all our own."

To begin with it is necessary to at least take note of one reason why Taraki regards the Western press as unashamedly "imperialists and propagandistic," a reason that goes a long way toward explaining his expressed antipathy to the Western powers.

The press coverage of the Afghan revolution has been - and I take my own share of the blame - fairly appalling. The initial reports sent out from Kabul, of thousands dead, of violent revenge likely to be brought down on tens of thousands more, now appear to be untrue.

It was a bloody coup, without a doubt, but the figures suggested by diplomats based in Kabul, and faithfully passed along by reporters who assumed the diplomatic community actually knew something of the country, were probably worng by a considerable margin.

The exaggeration, the fault of those of us who perpetrated it and of those embassies who planted the ideas in the very receptive minds of the reporters, triggered angry denials from the new government, denials which some of the more hard-live politicians in the Western capitals might regard as a confirmation of Taraki's political outlook - pro-Soviet and violently anti-capitalist.

My own belief, having listened to Taraki's rather gentle explanations of his seizure of power, is that his views do not support this facile assumption. It seems more probable that the democratic republic, so called, has genuine non alignment as its aim. Whether the Soviet Union will permit such a posture remains to be seen.

Afghanistan before the coup was a country yearing for revolution. Its deposed monarch's power and influence lingered on under Mohammed Daoud - a man who was brother-in-law to the exiled king. Men like Taraki, and other leftists like Babrak Karmal and the new government's only woman, Dr. Anahita Ratebzad, found Daoud's apparent sympathy for the aristocracy galling. When TarakI was arrested three weeks ago the mood that had been building, for two years according to the new premier spilled over into military action.

What followed was the ultimate expression of two years of pent-up rage - something which not a single Western embassy seems to have spotted, but which the Indians, to their credit forecast months ago.

If India understood why the coup took place, so is it also offering advice and help to Taraki in his rather confused first days of power. The press conference arranged on Saturday came about after pressure from New Delhi "not to let the West think you've all got three heads," as one Indian put it.

The view from New Delhi that Taraki and his 20 cabinet colleagues are agrarian reformers, intensely nationalistic and likely to be formidably opposed to direct Soviet intervention, is, in my opinion, a correct assessment."

"Give them six months, and let's see how they shake down," said one Indian. "It is fruitless to make any snap judgments about the Afghans."

That seems good advice. If Taraki appears to regard the West as more imperialists, and the Western press as purveyors of propaganda, who can blame him?

If, as seems likely, a long-expected coup took place with relatively little loss of life, and reports in London and Washington speak of butchery and unprincipled Marxist savagery, who can blame him for retiring, hurt and angry, to take counsel with the Russians and the Cubans and the Czechs?

The west should have understood that Afghanistan wants and needs help and support - financial, economic, moral. If Taraki is snubbed on the basis of a snap judgment made in the confused aftermath of the violence, it will be doing him, and the undoubtedly oppressed peoples of an important little land, a grave disservice - a disservice the West may one day regret.