President Clinton's national security adviser yesterday attacked the "isolationist right" wing of Congress, a group that he said has embraced a "distinctly defeatist" worldview and is imperiling American leadership abroad.

In a speech to the Council on Foreign Relations in New York, Samuel R. "Sandy" Berger delivered what aides called a broad rebuttal to the conservative forces who last week defeated ratification of the Comprehensive Test Ban Treaty.

The proponents of this "new isolationism," Berger said, believe in a "survivalist foreign policy--build a fortified fence around America, retreat behind it."

In a prepared text released in advance of the speech, Berger argued that the administration's opponents in Congress are animated by an "impulse to withdraw from the world in a way that would squander our advantages, alienate our friends, diminish our credibility, betray our values and discredit our example."

While Clinton, Berger and Secretary of State Madeleine K. Albright often speak broadly in favor of U.S. engagement overseas, the national security adviser's comments were remarkable for their bluntness and stinging rhetoric. This reflected mounting frustration not only with the defeat of the nuclear pact, but also with the administration's recurrent difficulty in winning congressional approval of increased spending on foreign aid and State Department operations and payment of U.S. debts to the United Nations.

Although isolationism is not a majority view, Berger said, "we must face the reality that it no longer is a fringe view. In fact, it is the view of a dominant minority in the Congress."

But House Majority Leader Richard K. Armey (R-Tex.), in a statement, dismissed Berger's remarks as "random name-calling by a frustrated administration" annoyed by "its own missteps."

Other Republicans have noted that even avowed internationalists such as Sen. Richard G. Lugar (R-Ind.) voted against the test ban treaty, and some blamed the administration for mishandling the ratification vote. Moreover, in his focus on the ideological right, Berger did not mention that forces in the Democratic Party handed Clinton one of the principal policy setbacks of his second term--the failure to win "fast-track" trade negotiating authority in 1997. This year, Clinton has shied away from confronting doubts in his party about letting China join the World Trade Organization.

Berger noted that even many people abroad are wary of U.S. activism. In a remark that may ruffle some feathers overseas, he mocked "Europeans who flock to fast-food outlets and then complain about the threat of 'McDomination' to their 'cultural sovereignty,' " as well as "Asians who decry the superficial materialism of American culture but then compete to build the biggest skyscrapers."