T. Main, Perkins claims to have advised the World Bank, United Nations, IMF, U.S. Treasury Department, Fortune 500 corporations, and countries in Africa, Asia, Latin America, and the Middle East.

Mallaby, a member of the Council on Foreign Relations, holds that Perkins' conception of international finance is "largely a dream" and that his "basic contentions are flat wrong".

[5] Articles in the New York Times[6] and Boston magazine[7] have referred to a lack of documentary or testimonial evidence to corroborate the claim that the NSA was involved in his hiring by Chas T. Main.

After an extensive investigation, the New York Times concluded that "the arc of Mr. Perkins's career seems to be described accurately", although they did not find evidence to support "some of his fancier claims," including those involving the NSA.

T. Main's former vice president Einar Greve, who first offered Perkins a job at the firm,[4]: 10  agreed that foreign debt represented a poor economic strategy for developing nations:[8]Basically his story is true.… What John's book says is, there was a conspiracy to put all these countries on the hook, and that happened.

[7] Boston Magazine noted that Perkins can provide little documentation to support his claims of international intrigue, describing a largely unconvincing "flimsy package of materials.