WASHINGTON  For years, they have been one of the most formidable lobbying forces in town: the elite band of former members of Congress, former diplomats and power brokers who have helped Middle Eastern nations navigate diplomatic waters here on delicate issues like arms deals, terrorism, oil and trade restrictions.

Just last year, three of the biggest names in the lobbying club  Tony Podesta, Robert L. Livingston and Toby Moffett  pulled off a coup for one of their clients, Egypt. They met with dozens of lawmakers and helped stall a Senate bill that called on Egypt to curtail human rights abuses. Ultimately, those abuses helped bring the government down.

Mr. Moffett, a former congressman from Connecticut, told his old colleagues that the bill “would be viewed as an insult” by an important ally. “We were just saying to them, ‘Don’t do this now to our friends in Egypt,’ ” he recounted.

Now the Washington lobbyists for Arab nations find themselves in a precarious spot, as they try to stay a step ahead of the fast-changing events without being seen as aiding despots and dictators. In Libya, Saudi Arabia, Bahrain, Yemen, Egypt and other countries in the region, leaders have relied increasingly on Washington’s top lobbyists and lawyers, paying them tens of millions of dollars. Some consultants are tacking toward a more progressive stance in light of pro-democracy protests, while others are dropping their clients altogether because of the tumult.