Soviet President Leonid Brezhnev received two very different kinds of welcome on his visit this past week to Czechoslovakia.

A 100,000-strong rent-a-crowd of school children and factory workers was turned out to applaud him at the airport, and to wave banners proclaiming eternal friendship with the Soviet Union.

But Prague citizens - prevented by traffic chaos from going home after work - watched from the curb in eerie silence as horn-blaring police cars followed by Brezhnev's tank-like limousine roared through the streets.

No one waved. No one cheered. They just stared, totally impassively, giving resigned shrugs and smiles after the motorcade had gone by.

It was in a way symbolic of the state of Soviet-Czechoslovak relations 10 years after Brezhnev sent half a million troops to crush "Prague Spring" - Czechoslovakia's eight-month experiment in what its supporters called socialism with a human face.

An undemonstrative people accustomed to foreign rule, the Czechoslovaks can fairly easily be suppressed and even brought out on the streets by a Communist party that is once again all-powerful. But they cannot be forced to show any enthusiasm for a system of government that runs against their national traditions.

Clearly timed to coincide with the 10th anniversary of "Prague Spring," the Soviet leader's visit was confirmation that Czechoslovakia has regained its former status as one of the most docile of Soviet satellites.

Western observers believed the main purpose of the visit, Brezhnev's first since 1973, was political. "Here he is, 10 years after he invasion, returning with a sense of triumph. He is flaunting to the outside world that Czechoslovakia is firmly back in the Soviet orbit - a position which in his mind vindicates the decision to send in troops," commented a senior Western diplomat.

"The regime here has recently been talking about the invasion much more freely. They foresee there's going to be a good deal of hostile comment on the anniversary itself - and they've decided to meet it head-on," remarked a Western analyst.

Part of the campaign is to stress the way in which life has returned to normal in Czechoslovakia following the liberal upheaval and the later clamdown. The country is being projected as the Soviet Union's staunchest ally - symbol of which was the choice of a Czechoslovak, Maj. Vladimir Remek, as the first non-Soviet cosmonaut.

Indeed spring 1978 in Prague is marked by a normality of sorts. scruffy artists squat on Charles Bridge and sketch the sun setting behind Hradcany Castle. Two young Czechs caress a pair of Russian girl tourists in a discotheque - and promise to meet again "in Moscow." Each weekend Czech families leave the city in droves for their weekend cottages in the Bohemain countryside.

At the same time, Brezhnev's provided fresh evidence that supervising this normality is one of the most heavy-handed police apparatuses in Eastern Europe. While posters of the Soviet leader and red flags were being pasted in every shop window shortly before his arrival, over 25 supporters of the Charter 77 human rights group were being picked up by police at their homes. Others claimed they were beaten up by thugs in the streets in an apparent attempt to discourage them from protesting.

As it was, the dissidents had to wait until after Brezhnev's departure before issuing a statement accusing the police of continued daily repression.

Despite the publicity they receive in the West, the dissident intellectuals pose less of an imminent danger to the regime than growing economic problems. The very real that Czechoslovakia - once the workshop of the Austro-Hungarian empire - may be losing its competitive position as the most developed of the socialist states together with East Germany was undoubtedly an important item in the talks between Brezhnev and Czechoslovak President Gustav Husak.

Explained a Western diplomat: "The economy here is the most political subject of all. If the economy goes wrong - and there are signs that it is going wrong - there could be serious trouble for the regime. What little popularity Husak has is based on his ability to provide bread and circuses for the population. If that goes, his position will become very difficult."

Most worrying of all for the Czechoslovak rulers is the Soviet refusial to continue subsidizing the country's economy through supplies of relatively cheap energy. Not only has the Soviet Union announced it cannot continue to expand oil deliveries at the previous rate (already forcing Czechoslovakia to look to the Middle East) but by 1980 the price of Soviet oil will reach the world level.

This decision is affecting all the Eastern bloc countries - but could be critical in Czechoslovakia's case. It was hardly a coincidence that accompanying Brezhnev was the Soviet Minister for power generation and electrification, Pyotr Neporozhny, who discussed the development of nuclear power with Czechoslovak officials.

Finally, Brezhnev's visit of Czechoslovakia is seen as his endorsement of the leadership of Husak who took over as Communist Party first secretary from his predecessor. Alexander Dubcek (now working as a clerk in Bratislava) in April 1969.