THE NEW AGREEMENT on military bases with the Philippines is an embarrassment worth the stomaching. It's an embarrassment, particularly to the Carter administration, because of the nature of the Marcos government: a military dictatorship with a raft of poorly tended social and economic ills, a blighted human-rights record and at least one-and-a-half serious insurgencies. President and Prime Minister Ferdinand Marcos would not be human if he did not figure to exploit the agreement as evidence of American suport for his rule. The Catter people will have to grimace and bear it.

The agreement, technically amendments to an agreement running to 1991, is nontetheless justified -- on strategic grounds. It assures the United States of use for at least five more years of the Subic Bay naval base and Clark air field, installations necessary for a variety of military/political purposes in the Asia-Pacific region. And it conveys to all and sundry U.S. determination to remain part of both the regional and global balance of power. This is particularly valuable showing to make at a moment when Peking and Taipei, for their different reasons, desire an affirmation of American constancy in Asia, and when many other countries around the world are looking to see how the United States responds to the march of Soviet power. Mr. Carter did not have to be reminded that large swaths of the American public, and not just his critics, are looking, too.

There is a certain political symmetry to the financial terms: The administration promises to compensate the Philippines with security assistance ( $500 million worth over five years) at triple the current rate, but this is only half the total of military and economic aid that the previous administration ahd offered. (President Marcos, guessing wrong, rejected that earlier offer.) Otherwise, the agreement satisfies the current requirements of the Philippines for exercise of sovereignty and those of the United States for operating flexibility; these things change. It is, in short, a good agreement, and the Congress, while continuing to remind Mr. Marcos of his domestic failings, ought to go along.