The domestic United States political reasons for opening a new round of Soviet-US talks are so obvious that there is danger of overlooking the nugget of real value that may lie within.
Let's clear away the obvious first.
The Democrats can make little hay against President Reagan this year on the issue of economics. The economic recovery plus the absence of a revival of inflation have largely neutralized that issue. The only promising issue for the opposition as the political year opens is foreign policy.
That is where the eight Democratic hopefuls who appeared on television last Sunday work the hardest. Their strategy is to accentuate a feeling of public anxiety about the danger of war. Polls have indicated that the anxiety exists at the top of the list of popular national concerns. President Reagan entered the new year politically vulnerable to attack on this flank.
Hence it was as certain as day following night that the political year would open with Mr. Reagan discovering that an East-West dialogue is a good thing and that he would like to have more rather than fewer talks with the Soviets about matters of ''mutual interest.''
The most important point, politically, in his speech was the assertion that all of us are safer because of his weapons-building, that there is no real danger of war, and that because of the new weapons we can expect to get a better deal out of the Soviets now than could have been possible three years ago.
The merits of that position are arguable, but that does not matter politically. Mr. Reagan did to some extent neutralize the value of the ''fear factor'' by his assertion, and even more by coming out in favor of dialogue. If he is now able to get going a real dialogue with substance in it, he will have enormously reduced his opening vulnerability on the foreign policy issue. He might even be able to turn it into an asset.
That brings us to the question of what response we can expect from the Soviets. If they accept Mr. Reagan's invitation to the peace dance, they will of course be doing him a big political favor. That must be the main argument in Kremlin discussions against joining the dance.
But there will be arguments in the Kremlin on the other side. On balance what the Soviets like to call the ''correlation of events'' is not currently running in their favor. Their economy is doing poorly. The burden of their arms program is one reason. Their invasion of Afghanistan is still incomplete, after four years. It has offended the Islamic world and China. It has worried India and led to a cooling in Soviet relations with India. And Moscow would find it economically difficult to match and keep up with the new American arms program.
When the Soviets weigh these factors one against the other, they will of course also be watching Mr. Reagan and calculating his political intentions and prospects.
Obviously, the Soviets will do nothing until they know definitely whether he is running for a second term. If he should decide to retire, they would of course put all serious business with the United States on ice until the next president was elected. It is an old rule in power politics that you never do business with the old ruler, only with the new one.
If Mr. Reagan is definitely going to run (he has promised to tell us on Jan. 29), then the Soviets will want to calculate his prospects of winning. If they conclude that he is the likely winner, then they might well decide to accept his invitation to dance.
In that case they might invite Mr. Reagan to visit Moscow for a ''let's get acquainted'' visit. That would make sense. A visit does not have to be called a ''summit.'' The conventional theory is that summits should not be undertaken without solid prospects for important accomplishments. It is difficult to think of much in the way of important business which could be transacted during the coming year.
Even if both sides wanted to get going again on limits on nuclear weapons, the experts would need probably at least a year to work out new positions. Things like this are not done in weeks or even months. But just a visit, even if it led only to a promise to make a new start on weapons limitations, would be reassuring to all people of the world. It would reduce strains in the NATO alliance. And, of course, it would deprive the Democrats of a chance of running effectively against Mr. Reagan as a ''man of war.''
The speech opened the dance. Now we wait to see whether the Kremlin decides to waltz.