THE HOUSE vote to stop the international development banks from using American money to aid a clutch of countries currently out of congressional favor is a nasty piece of mischief that ought to be promptly undone. The purpose of those banks - one that the United States accepted by joining them and one that serves American interests well - is to put some political distance between poor-country development and rich-country diplomacy. Donors have plenty of other means, including direct aid, for conducting their bilateral diplomacy.No donor, least of all the one claiming world leadership, should lightly savage the imperfect but vital international institutions set up to transcend individual nations' limitations. The latest effort to do so, started by an amendment of Rep. C. W. Young (R-Fla.), is no more enlightened than earlier attempts. As an expression of good (international) citizenship, it is rather like cutting down a tree in a public park.

In a sense, the Carter administration is the source of some of its own discomfort. By approving the earlier Reuss amendment instructing the U.S. government to use its voice and vote in the banks to advance human rights, it inadvertently encouraged those who see no harm in turning the banks to an American political purpose. The conservatives who sponsored the Young amendment, mostly as a device to punish Vietnam, carried the day only by snaring liberals susceptible to the argument that Vietnam has a miserable record on human rights.

The Young amendment assaults the integrity of the international banks, since they can neither remove American funds from the common pots from which they lend nor bow to an American dictate and halt lending to members (the Indochinese, Uganda, Angola, Mozambique) otherwise being treated by agreed-upon standards. Moreover, the amendment (passed without hearings) provides no procedures for altering the objectionable practices of the cited countries. It does not even say what the practices are .

We hope that either the House-Senate conference or the banks' lawyers can find a way out of this bind. Regardless, the Young amendment - passed by a 295-to-115 vote in which most Democrats joined the majority - ought to be read by the White House as a gale warning. This amendment is not merely the latest foreign-policy question on which a headstrong Congress has reacted sharply against an administration it perceives as too liberal, too ambitious and too aloof. It is another case in which a well-organized Republican minority has gotten the jump on the President - and on the Democratic leadership on the Hill. Mr. Carter does not yet have his international act together. He doesn't have all that much time.