WASHINGTON — Senator Obama is standing by one of his top foreign policy advisers, Zbigniew Brzezinski, despite concerns that aligning with the former aide to President Carter will undermine Mr. Obama’s support with the pro-Israel community.

Mr. Brzezinski, who served as national security adviser in the Carter administration, introduced Mr. Obama before a major policy speech on Iraq yesterday in Iowa, where the Illinois senator praised his work on the Camp David Accords and called him “one of our most outstanding thinkers.”

Mr. Obama’s embrace of Mr. Brzezinski has angered some supporters of Israel put off by Mr. Brzezinski’s criticism of the Jewish state in recent years and his praise for the authors of a book that condemns the influence of the “Israel lobby.” Mr. Obama’s campaign has disavowed the book, “The Israel Lobby and U.S. Foreign Policy,” by John Mearsheimer and Stephen Walt.

A Harvard law professor and supporter of Senator Clinton, Alan Dershowitz, said Tuesday that Mr. Obama had “made a terrible mistake” by aligning with Mr. Brzezinski.

A spokeswoman for the Obama campaign, Jennifer Psaki, yesterday pointed to the fact that Messrs. Brzezinski and Obama both opposed the Iraq war from the beginning, unlike Mrs. Clinton, and she suggested the Clinton camp was trying to smear Mr. Brzezinski.

Given Mr. Brzezinski’s opposition to the war, she said, “It’s not terribly surprising that those who embraced the war would try to discredit him now.” Ms. Psaki added: “Barack Obama has a strong record in support of a secure Israel and he will continue to foster a strong U.S.-Israel relationship when he is in the White House.”

The Clinton campaign declined comment.