West Berlin — The local pubs do a leisurely business catering to neighborhood skat players. Turkish boys play tricks on each other on their way home from school. The traditional Christ-child street fairs - ''over there'' in East Berlin as well as ''over here'' in West Berlin - draw their quota of youthful rubber-bumper car drivers and cotton-candy eaters.
And over it all on this crisp, sunny December day preside the East German watchtowers and the wall that for 23 years has scarred the Berlin landscape.
It is, in short, an ordinary day here at Checkpoint Charlie. And that is noteworthy.
Soviet-bloc retaliation for the NATO deployment of new missiles beginning this month stops dramatically short of the one move that could really hurt NATO's key deploying country: pressure on West Berlin and on East-West German relations.
West German observers are undecided as to whether to explain this restraint more in terms of Soviet courting of the Western peace movement (and the Bonn government), vacillating leadership in the Kremlin, or the palpable Eastern European reluctance to sharpen East-West tensions. They tend to credit all these reasons, in varying degree.
Certainly Moscow wants to move carefully in its encouragement of antinuclear movements in Western Europe - especially in the one NATO country it has expressed the most concern about, West Germany.
Such Soviet nurturing of the European antinuclear movement requires sufficient Soviet toughness to confirm the protesters' belief that the NATO deployments greatly increase East-West tensions and the risk of war.
At the same time, however, it also requires that Moscow not sound so threatening as to frighten away those West German moderates who swelled the demonstrators' ranks to an impressive 1 million this past fall. And there are few actions that would rally West Germans against the Soviet Union faster than tampering with the guaranteed transport and political links between West Germany and West Berlin.
The history of the 1948 Berlin blockade and of Soviet Premier Nikita Khrushchev's 1958-61 Berlin ultimatums provides convincing proof of this axiom. Hence the current immunity of West Berlin - and East-West German human contacts - to current Soviet pressure.
By the same token the Soviet Union does not wish to push the West German government too far. It needs the West Germans as its most important suppliers of Western technology. Especially in a period when superpower relations are at their worst in 20 years, it also needs the insurance of some continued East-West dialogue that West Germany provides.
Although Bonn is now governed by conservatives rather than Social Democrats, this Soviet-West German interdependence has not changed. The rightward shift in Bonn a year ago might have tempted the Kremlin to increase the stick at the expense of the carrot - since Chancellor Helmut Kohl made it quite clear no Soviet carrots could deflect him from the missile stationing.
Rhetorically, Pravda has blasted Kohl for pulling things out of the ''garbage heap of the cold war.'' But in practice Moscow is treating Dr. Kohl exactly as it did his predecessor, Helmut Schmidt. But Washington does not suspect the West German conservatives - as it did the Social Democrats - of incipient betrayal of the West in those dealings with Moscow.
These considerations limit the Soviet retaliation for new NATO missiles to deployment of new short-range missiles in East Germany and Czechoslovakia. This pressure is minimal, for three reasons:
* Despite Soviet rhetoric, there is no sign the Soviet Union is accelerating its short-range missile stationing in response to NATO's deployment of Pershing II and cruise missiles. The short-range Warsaw Pact modernization began well in advance of the NATO deployments. Some 36 Soviet SS-21s have been installed in East Germany over the past nine months, according to NATO sources. More are arriving at the rate of four a month.
* These short-range missiles hardly increase what is already a saturation Soviet threat to West Germany and Western Europe - especially through the 243 Europe-targeted SS-20s, which are the reason for the new NATO missiles.
* Moscow is giving equal propaganda play to its new short-range missiles in Eastern Europe and to its implied increase of nuclear missile submarines off the coast of the US. Paradoxically, this serves to ''couple'' rather than ''decouple'' the defense of Europe and the US - which was the very aim of the new NATO missiles.
The upshot, then, is no effective increase in Soviet pressure on Western Europe or on West Germany in this period of NATO stationing. If anything, the pressure of momentum is shifting to favor the West in what will soon be the fait accompli of the first Pershing and cruise deployments. Inertia favored the Soviet Union as long as the Western stationing had not yet begun.
Now that the hurdle of the initial de-ployments is almost over - only a few hundred demonstrators are still protesting the US missiles at the Pershing base in Mutlangen - further deployments will hardly summon as intense public opposition as the first installations did.
Paradoxically, again, the Soviet avoidance of leaning on Berlin and East-West German relations only reinforces this trend. If East-West confrontation is not visibly worse after NATO deployments, then for many West German citizens the antinuclear cause loses its urgency.
There is another factor in current Soviet conduct: the uncertainties of the Kremlin leadership during the drawn-out illness of General Secretary Yuri Andropov. If jockeying for position is going on, an indecisive Soviet policy consisting partly of threats and partly of business as usual may well constitute the minimum consensus every Politburo member can agree on and no one needs to stick out his neck for.
A final factor explaining Soviet conduct may be the unusually public softening of Soviet threats to the West by Moscow's Eastern European allies. East German party and state chief Erich Honecker bluntly told his Central Committee last month that ''we are for limiting the damage (of the NATO missile deploy-ments) as much as possible.''
Romanian party and state chief Nicolae Ceausescu openly contradicted Soviet insistence that British and French national missiles should be included in the NATO-Warsaw Pact balance.