At the London summit this weekend, President Carter goes up against three imporatant allied leaders to whom he has done political dirt. Since none of them can stray far from the American fold, the outcome of the encounter - and indeed the London meeting as a whole - is no big deal.

But it will be interesting to see if the President can soothe hurt feelings. For to do so he will have to curb the impatient personal impulses that have hitherto dominated the foreign policy of this administration.

Carter came to the While House without any serious experience in international politics. Most of his ideas were developed in a presidential campaign as immoral and foreign to AMerican tradition the policies of Henry Kissinger.

Carter emerged from that experience with a number of pet notions that he believed to be touchstones of right and wrong inforeign poicy. Among other things he wanted more emphasis on human rights and less support for governments that violate them; a ban or slowdown on shipment of arms, expecially the stuff from which nuclear weapons can be made; and more cooperation with allied countries in solving common problems, particularly of economic management.

During his first days in office Carter set out these views in ringtin public declarations. But foreigners have the peculiarity of being foreign. What seemed to Carter simple and eternal verities posed political problems for the leaders of West Germany, France and Japan.

Chancellor Helmut Schmidt was annoyed, first because the Carter stance on nuclear proliferation cut against German plans for energy development in general and a deal with Brazil in particular; second because the human-rights statements compromised Bonn's quieter (and far more successful) approach to the COmmunist world; and third because in economic matters he felt he was being lectured like an errant schoolboy.

President Valery Giscard d'Estaing was made to look bad with France's Gaullist because pressure on arms sales, relations with undemocratic governments, and transfer of nuclear material compromised Gallic independence - the more so since Carter seemed to be reviving with the British the old Anglo-Saxon alliance so poisonous to France-Firsters.

Prime Minister Takeo Fukuda was weakened, first by Carter's insistence that Japan forego plans for development of nuclear reprocessing plant; next by a lack of support for the Japanese connection with the not-exactly-democratic regime of South Korea; and third by economic arguments that came out to mean self-impposed tariff barriers for Japanese exports.

Soothing these wounded feelings is not, in itself, nearly so important as the Allies-uber-alles school of AMerican diplomacy imagines. Germany and Japan, and even France are dependent upon AMerican support in security matters. Their governments are not going to jump to the Communist side even if Carter hangs tough.

Nor is there that much international business that depends upon tight cooperation among the allies. At the absolute best, if everything goes swimmingly, the London summit will yield a joint declaration supporting free trade and energy conservation, a common determination to help the poorer countries and a synchronization of effort to maintain prosperity without inflation.

But it is not all that hard for Carter to patch it up with the three disaffected allied leaders. He chiefly has to show an understanding for alliance politics - a realization that what are pet projects to him present serious problems to other leaders. GIven that understanding, he and hte allied chiefs can work together quietly to meet political problems in ways that do the least damage to all parties.

Whether Carter is willing to be that accomodating, however, does represent an important test - indeed the true significance of the London summit. For if he does not move to accommodate, then American policy will continue to move in eccentrie ways. If he does soften, then there is a chance that the President's advisers can guide him back to a policy that will sit better with traditional friends and be less confusing to the rest of the world.