Vienna — The East Europeans seem more concerned about US-Soviet tensions than at any other time since the cold war. Their concern is fueled by the possibility that the current Geneva talks will not produce an arms control agreement in time to prevent NATO's planned deployment of new missiles in Western Europe. This, in turn, East Europeans fear , will prompt Moscow to deploy ''retaliatory'' Soviet missiles, making the outlook worse still.
The anxiety is not so much that the Soviets might respond to NATO's new cruise and Pershing II missiles (themselves a response to the buildup of Soviet SS-20 rockets) by placing their own hardware in East Europe. Well-informed sources prepared to discuss so sensitive a field of Soviet policy with outsiders say flatly that that is not in question - for both military and political reasons.
What does keep the East Europeans awake at night is the knowledge that, whatever the Soviets decide in terms of new weapons placements, it can only mean:
* An even more perilous escalation of the arms race.
* Adverse effects for the East Europeans themselves.
Predictably, the most uneasy East-bloc countries are the reformers, especially Hungary. The Budapest regime has not only a well-established, market-oriented economy, but also a considerable measure of domestic political latitude.
But other East Europeans have ground for concern. The Poles, amid heavy Soviet pressures already, are at last attempting the first difficult steps toward economic reform.
In Czechoslovakia, some tentative experimentation is afoot despite hard-line opposition. Countries like Hungary and Romania have irreplaceable economic and commercial links with the West.
All these would be at stake if the Soviets ordered the bloc to toe a tougher line toward the West.
All these would be at stake if the Soviets ordered a tightening of ship throughout the bloc.
It would cramp more moderate thinking among East Europeans who have distanced themselves from standard Soviet propaganda, which puts all of the blame for the present deadlock on the Americans.
Again, the most evident example is Hungary, which behind the scenes is a strong advocate of negotiation - and, moreover, continued negotiation between Moscow and Washington, even if NATO commences cruise and Pershing deployment by the end of the year. The Hungarian Communist Party leader, Janos Kadar, is said to have pressed this argument on Soviet leader Yuri Andropov during his long visit to Moscow in the summer.
Some East Europeans of political standing even argue the present situation is so dangerous that, regardless of culpability, the Soviets must show more ''give'' if the stalemate is to be broken.
Such sources are in every respect loyal to the Soviet alliance. For evident reasons they prefer not to be identified, but privately they say the Soviets missed their opportunity in the last, ''tired'' Brezhnev years.
''Nothing was really happening, nor was really decided,'' one said recently. ''It's a great pity Andropov did not have those last few years.''
These sources also see the West as making the same mistake today that it did in the 1960s with Nikita Khrushchev, in not taking Mr. Andropov more seriously and ''giving him a chance.''
The Soviet Army presence in Poland, Hungary, and Czechoslovakia has thus far been unobtrusive. Over the years, people have come scarcely to notice it. But any visible enlargement of that presence with missile sites, an East European said, could rekindle old resentment and create difficulties for their communist regimes that, in turn, could embarrass the Soviets.
There has been some speculation the Soviets might want to install missiles in East Germany and Czechoslovakia, possibly even Hungary. But ''it doesn't make military sense,'' an East European said, ''and politically it would not be sensible either.''
It is widely believed that any Soviet countermove would most likely be made in the eastern regions of the Soviet Union, with missiles targeted on the United States. That, however, does nothing to diminish East Europeans' overall misgivings. And these worries have been heightened by Andropov's blast at the US last week.
It seems highly probable the Hungarians have Andropov's ear more than other East Europeans, partly because of his diplomatic experience in Budapest in the mid-1950s but also because of his open interest in their reforms. Their views, therefore, seem to carry some weight.
Hungarians appear convinced that Andropov has encountered much more difficulty in breaking through the rigidity of the Soviet bureaucracy to encourage innovation and to establish clear ascendancy over the military than he himself anticipated.
''The West,'' an informed ''liberal'' source grumbled, ''should realize that and take it more into account if it wants to encourage flexibility.''