The PROBLEM for Washington in dealing with most Latin countries, whic are small and often materially or psychologically dependent on the United States, is to treat them fairly without over-whelmong them. In respect to Panama and the Dominican Republic, it is evident how just how tricky this problem is.

To put a proper flourish on the new Panama Canal treaties, Mr. Carter agreed to go there and hand over formal title. This has occasioned protests, some violent by Panamians, who accuse the president of bolsteing strongman Omar Torrijos, and by the same and other Panamanians, who find the treaties, as they found the American ratification process, offensive to their nationalism. Should President Carter have stayed home? Hardly. One must acknowledge, however, that the new treaties, fair and right and essential as they are, will not in themselves calm the Panamanian scene. There is no way the United States can tranquilly maintain, even in the new form, its huge political and economic presence. It is like moving an elephant from one room of your house to another: The elephant is still in the house.

The Dominican Republic offers another facet. Some generals have been thwarting replacement of 12-year president Joaquin Balaquer, handpicked by Washington to end the crisis of the American intervention of 1965-66, by Antonio Guzman, who trounced him in the recent elections. A personal warning by Jimmy Carter was necessary to head off a steal last month, and the people of the Domican Republic have still not been assured that their political will is being respected. Perhaps the military does ot so much want to nullify the election as to extort from Antonio Guzman assurances that their perquisites (profitable import licenses and the like) won't be lost. In any event, if the election si stolen, whether by a clear theft or by disarray flowing from delay, there could be disorder and even civil war. How can Washington bring its influence most effectively to bear? By all-out political pressure, which risks charges of intervention, or by subtle maneuver, which risks letting the military's caper succeed?

In Latin America, but not only there, no great feats of statesmanship wait to be accomplished that will clear the air and lead to a diplomatic kingdom of heaven. There is only a more modest requirement for constant attention to shifting circumstances and political detail - "gardening," as it has been aptly called.