THE ACHIEVEMENT OF the Bonn meeting is that it has kept matters from getting worse. That's not a bad thing to have managed. Perhaps that final communique, with its talk about cooperation, and meeting again next year, will not seem very exciting to you. But it's better than the alternative. The strains among these seven rich and powerful economies area real, and each of the seven men at Bonn could score a sharp advantage at home, at least briefly, by exploiting those strains as political issues. But each of the governments at Bonn remembers that there was a period, between the two world wars, when they let economic conferences turn out badly. The recollection of that catastrophe is the discipline that now keeps the seven together.

The seven governments are apprehensive about what is known as world opinion - which, first of all, means the currency markets. The people who manage and invest large sums of money provide a running commentary, through the exchange rates, on countries' varying economic prospects. A lot of these people wanted some kind of assurance from Bonn that the governments were somehow going to try to stabilize the currency rates and make the markets safer. The message to the markets is that, just as the United States has been saying all along, it really isn't possible any more. Before currencies become more stable, inflation rates will have to be brought down and trade deficits reduced. That subject leads to the subject of oil imports.

The Bonn meeting was deeply interested in President Carter's energy bill for reasons that go well beyond energy. Abroad, this country's failure to put the president's policy into effect has seemed an ominous indication of an American refusal to exercise even a modest degree of self-restraint in behalf of common interests. In response, Mr. Carter made a specific pledge. He intends to get the price of American domestic oil up to world level by the end of 1980. For the consumer, at present prices, it would increase the cost of oil products about a nickel a gallon.

But the entangled argument over how, or even whether,to do it has immobilized the central section of the central section of the Carter energy plan in Congress, Mr. Carter's first choice is a tax on crude oil. But that oil-tax bill has been stuck fast in the Senate ever since it passed the House nearly a year ago. Mr. Carter's declaration in Bonn strengthens the impression that he has decided to give Congress until the end of the session to enact legislation. If it fails, the implication here is that he proposes to proceed under presidential authority. It is not clear precisely what route he has in mind. But the Bonn communique says that he is still determined to achieve the goals of his original bill, if not by the bill then by other means.

Each of the other six nations responded in kind. Crucial to all the rest, Chancellor Helmut Schmidt agreed to try harder to speed up Germany's, and therefore Europe's, economic expansion. Faster expansion in Europe and Japan would reduce the U.S. trade deficit and strengthen the dollar. Last year it didn't work. This year everyone is going to try harder.

The prevailing mood at Bonn was, evidently, one of caution. The seven politicians all know that their economies are no longer predictably following the established and familiar patterns of the postwar decades. Since they have all been burned by recent economic surprises, caution is not necessarily an unreasonable posture for the present. All seven governments are now uneasily coming to terms with the possibility that the last recession was not merely an unusually severe turn in the accustomed cycle. Perhaps, instead, it announced a new phase in the world's development - one in which, conceivably for quite a long time, economic growth will be slower and rises in living standards much harder to earn than in the long postwar boom that may now have ended.

The seven men at Bonn agreed to keep working together. They agreed to try to keep economic differences from turning into disruptive political issues. But they were trying not to promise more than they can deliver - and how much they can deliver, they are not sure.