You're Leonid Brezhnev and you're 74 years old, and you've been in power 16 years, and you're a lonely figure because most of your old comrades are dead, and you face a challenge in Poland and a new administration in Washington. So this is the way your throughts run:

The Brezhnev era has been a good one -- better than maybe any in Soviet history. Politically, there have been no upheavals. Khrushchev died in his bed. Challenges from others were put down without bloodshed. The dissidents have been divided and spread to the winds. At the last Party Congress, for the first time in history no changes in the Politburo had to be announced.

In economics, there have been problems -- a declining labor force and a slower rate of growth. But we have been able to make up for shortfalls by imports from Western Europe and the United States and other countries. The standard of living has risen steadily. There is no inflation and no unemployment. Russians have never had it so good.

Abroad, the Soviet Union has also made steady progress. Our armed forces are equal to, maybe better than, those of the United States. We have developed mobility, and we have bases and allies in places we never dreamed about -- Central America, southern Africa, Ethiopia and South Yemen, Libya and Syria, and Vietnam. The old nightmare, of course, remains -- encirclement by an alliance of the United States, Western Europe, China and Japan. But at the last Party Congress, I threw out proposals for all of them -- a summit meeting with Reagan, improvement of relations with the Chinese, trade with Japan, arms control with Western Europe.

In the meantime, I have to worry about the defense of the socialist camp. In the past, we were always able to step in and prevent states that had become socialist from slipping away. We did it in Hungary in 1956. We did it in Czechoslovakia in 1968. We did it in Afghanistan in 1979.

Poland, at first, looked not so bad. The Catholic Church there has been relatively independent all along. Agriculture was never socialist. So an independent trade union was nothing to fight about. Just reason for a dash of cold water.

But now the disease has spread to the party. The party leaders bargain with striking workers. They accept a union of farmers. They do not punish dissidents. They schedule party elections for July. What is happening in Poland is what almost happened in Czechoslovakia. The Polish party is becoming a party of social democracy.

That is not acceptable. What happens in Poland could easily spread to East Germany, and Hungary, and Czechoslovakia, and maybe even here in Russia. Anyhow, Poland is our historic security buffer -- the barrier against another blow from the Germans.

Of course, we do not want to have to fight. Better by far to turn the screw slowly. So we had the military maneuvers in March. So I went to the Czech Party Congress in Prague and applauded Husak when he talked of the determination of the socialist camp to stick together. So I sent Suslov to Warsaw last week to tell the Poles to shape up.

But they didn't crack under Suslov. Some of them laughed at him. So I have to think about going in. I have to try to count the costs.

The Poles say they will fight. But that's what the Poles said in 1956. That's what they said in 1939. That's what they said in 1863. That's what they always say.

The West Europeans claim it will be a different world, something unimaginable. But what can they do? Can the West Germans, with the economy sagging, stop trade? Can they break contacts with 17 million Germans in the Democratic Republic? And if the West Germans don't break off, then neither will the French nor the British nor the Italians nor the small countries.

The Americans sould different these days. Reagan is provocative. He says we will lie and cheat and steal to gain any advantage. He makes Haig, a general, secretary of state. His defense secretary, Weinberger, says if we go into Poland, they will arm the Chinese.

But what does that mean? The day Suslov visits Warsaw, Reagan lifts the grain embargo. The embargo was put on after Afghanistan. But nothing has changed in Afghanistan. And the Americans can't achieve anything soon by arming the Chinese. Probably they'll just do that, whatever I do. Anyway, there's no clear signal from America.

So what do I do? How do I preserve the Brezhnev era? What would Khrushchev have done? And Stalin? And the czars? What happens if I do nothing?