When the economic summit ended here a year ago it seemed to have accomplished little other than an outpouring of good will. In Jimmy Carter's first appearance as a principal on the international stage, he had acquited himself as a friendly partner in the process of economic cooperation with the goal of ending the recession.

The other principals wanted to give Carter, the unknown, the benefit of every doubt. They were prepared to welcome him to membership in the club of old hands long familiar with tough bargaining in the international arena.

When Carter returns to Europe for his second economic summit in Bonn in July, all that will have changed. His reputation badly battered at home, he is regarded in Europe with considerable skepticism. Above all, the failure to resolve America's energy crisis will weigh heavily on the president as he takes his place at the high table.

On this side of the Atlantic, they are not sure whether the fault is that of Congress or the president under the system of divided powers. They are asking why steps the executive might have taken, such as a tax on imported oil to reduce the ever-increasing flow, were not taken.

They put that together with gloomy reports of a possible new American recession late this year or early in 1979. The threat of rapidly rising inflation, perhaps even double-digit inflation, is another cloud on the Western horizon. What America does, or fails to do - and this we Americans sometimes forget - is of vital importance to the non-communist world.

The forthcoming summit is being masterminded by an able foreign-policy specialist, Henry Owen, who put together the agenda for the London session. The stress at Bonn, as Owen projects it, will be on combatting protectionism. The demand for protectionism is a political reality in every industrialized nation as competition for scarce markets increases. In this connection Owen is working closely with Robert Strauss, the anti-inflation boss and the chief trade negotiator.

Britain and France are among the principal offenders in the industrialized community. They have employed government subsidies heavily concealed to send their products into world markets at below-competitive prices.

The Japanese have been challenged on television sets and TV components and on specialty steels. Strauss has worked out so-called voluntary agreements to cut down U.S. imports in those two fields. Thanks to the rise in the value of the Japanese yen as against the dollar, U.S. imports of Japanese motor cars have begun to decline at the same time that American car sales have zoomed.

The skeptics writing off the summit of a year ago may have been premature. The stress then was on countering inflation, and Owen points to tangible results. In both Britain and France the rate has come down from double-digit, or close to it, to 7 to 9 percent. In short, they are close to what the mounting rate in the United States is today.

Will preaching against protectionism be of any avail with heads of government who are inevitably looking to the next election? Owen believes it can be effective just as was the warning against the perils of inflation at the last summit.

A second goal set for Bonn will be far more difficult to achieve. That is a persuade Germany and Japan to loosen the purse strings and take in a much bigger volume of imports. Those two prosperous - or seemingly prosperous - members of the club have resisted such efforts in the past.

Chancellor Helmut Schmidt, who will be the host to the Bonn summit, shares the deep-seated fear of inflation that is a part of the German psyche growing out of the disastrous inflation of the 1920s, which helped to bring Hitler and the Nazis to power. Germany has a phenomenally low rate of inflation (in the neighborhood of 3 percent). And Schmidt, a stubborn man, intends to keep it there.

Britain is basking in the glow of two bonanzas. Far and away the most important is the North Sea oil, a rich find that has begun to ease the costly drain of oil imports. It could mean that eventually the British will become oil exporters, although that day is distant and even improbable.

The second bonanza is the flow of Arab dollars into industry, banking and real estate. This is, however, a mixed blessing, since Arab spending sends prices up. Oil-rich Arabs never haggle over price tags, whether on a large country estate or the antique treasures on Bond Street.

Carter's second summit is one month off. Whether in the intervening weeks there can be some resolution of the energy impasse is a question the American visitor is asked. Agreement on de-regulation of natural gas has been worked out. But so many details still remain to be resolved in the package locked up in Congress that a settlement before July 14 is doubtful.