THE SENATE'S 92-to-0 vote for trade retaliation against Japan was an authentic and heartfelt expression of political frustration and anger. Americans keep buying more and more Japanese goods. American producers, losing sales to the Japanese competitors, bitterly complain to their senators that they cannot sell equally freely in Japan. Retaliation is usually the first response that springs to mind. Is that what the United States, in its own interest, now ought to try?

It's quite true that the Japanese do not run an open economy in the North American manner. Selling foreign goods in Japan is much more difficult than it should be. But the enormous widening of the American trade deficit is not Japan's fault.

Last year this country spent $37 billion more on Japanese products than Japan bought from Americans. That was more than double the deficit two years earlier, in 1982. But Japan's trade policies are no worse than they were in 1982. If anything, they are a little better. Japan is not buying any less from the United States than it did two or three years ago. It's one of the few countries in the world that is currently buying somewhat more.

The real source of this tremendous trade deficit is right here in this country. The United States is on a binge of borrowing and spending -- led, unfortunately, by President Reagan's budget. The continual borrowings by the U.S. Treasury push up interest rates, sucking in investment capital from all over the world. As that money is exchanged into dollars, it forces up the exchange rate.

As things now stand, the dollar is overvalued about 25 percent against the Japanese yen in terms of the goods that it buys. It's as though there were a 25 percent rebate on every Japanese product sold for dollars and a 25 percent tax on every American product sold for yen. Is it remarkable that Japanese sales here are soaring? The only surprise is that American sales to Japan haven't fallen.

Everybody in the Senate understands that the trade deficit is being steadily widened by the president's budget, now some $220 billion a year in the red. Some of those senators have been working hard for the past three months to try to push it in the direction of balance. They haven't made much progress so far. No wonder there's a lot of frustration at the Capitol.

Japan deserves reproach for its resistance to foreign goods. At home, it has never fully accepted the rules of open world trade of which, abroad, it is one of the world's greatest beneficiaries. But Japanese trading practices do not account for the dramatic and dangerous increases in the American trade deficit over the past two years.

It's entirely understandable that senators, constantly hearing people's grievances about foreign competition, would want to kick a foreign government. That vote last week was a symbolic gesture. You will know that the senators have begun to work seriously on a real remedy when you see them vote to cut spending and to raise taxes. That's what it is going to take to pull this country's foreign trade back into balance, and to restore fair competition in prices.