Before the presidential debates in 1980 between President Carter and Ronald Reagan, an irreverent journalist wrote:

"If I had the choice, this is the question I would put to Mr. Reagan:"Portugal is one of our major allies, because of the air base in the Azores. It has just escaped from a Communist attempted revolution, but is still very precarious and needs care and attention.

"Tell me, Mr. Reagan, what is the name of the prime minister of Portugal?"

The joke, of course, was that Reagan would have been quite unable to answer. He probably could not have given the name of the prime minister of Russia, and the suggestion was that a candidate for the presidency ought to know such things.

As it turned out, Reagan has not had to play much role in foreign affairs. There were no Camp David negotiations (Carter), or wrestling with the Soviets (Nixon), let alone Vietnam, all of which required presidential leadership.

Portugal has got on very well without Reagan. A few speeches, and leave the rest to George (Shultz, of course). Reagan's one attempt at personal diplomacy, the Reykjavik summit, was nearly a total disaster: He proposed giving away the nuclear deterrent. The other summits were just photo-opportunities.

But foreign policy is going to be an exceedingly important issue throughout the next four years. So here's a question for the first debate:

"Mr. Bush/Dukakis, what would you do as president to persuade the Soviets not to use force to reassert their control over East Europe when it collapses?

The communist governments of Eastern Europe have still no popular support, and once again the Polish government is on the verge of collapse. One more push might knock it over. First the prime minister, then the general secretary, then the party itself. And then what would Gorbachev do? A lot would depend on what the West did.

Let's hope Reagan isn't faced with the decision, and Lech Walesa and the boys hold off till after next January. Reagan would deliver a splendid speech, if someone wrote it for him, but this time a speech will not be sufficient. We are going to need a president quick-witted enough and determined enough to persuade Gorbachev to leave the Poles to decide their own future.

He can't be ordered; he must be persuaded. So, Mr. Bush, Mr. Dukakis, any ideas? That's the key question in foreign affairs, but there are others.

What to do about Cambodia? The Vietnamese, who have occupied the country since 1979, propose to withdraw by the end of next year. There's a real danger that if they do the Khmer Rouge will return and resume slaughtering the people. How can the United States prevent it?

What about the Philippines? The Aquino government, though staunchly pro-American, feels itself under domestic pressure to ask the United States to abandon its bases there. Jeane Kirkpatrick says invite the Japanese and Koreans to step into the breach. An interesting idea, with all sorts of historical wrinkles (the last time the Japanese were in Manila they killed a hundred thousand people).

What about it, George and Michael? The South American debt problem is once again building up to a crisis: Argentina, Brazil and Mexico between them are in hock for well over $250 billion and the moment may come, in the next year or so, when they all default together.

There goes Wall Street. What will you do about it?

So what will the debate be about? Why, Bush will accuse Dukakis of wanting to raise taxes and Dukakis will accuse Bush of failing to solve the drug problem. Bush will impugn Dukakis's patriotism and accuse him of letting murderers loose on the streets, and Dukakis will ask why Bush supported selling arms to the Ayatollah.

None of us will be any the wiser, nor will any of these matters indicate which of the two might handle the foreign policy crises which are far more serious than drugs or tax policy - let alone the Pledge of Allegiance. Ah well, perhaps someone will ask, innocently, "Who's the new prime minister of Poland?" or "Who's prime minister of the Soviet Union?"