Who is credited with writing an anonymous article about the soviet expansion plans that was influential in the creation of the Truman doctrine?

The anonymous article credited with influencing the creation of the Truman Doctrine is often attributed to George F. Kennan, although it was published under the pseudonym "X" in the journal Foreign Affairs in 1947. This article outlined the need for a policy of containment to counter Soviet expansionism, which significantly shaped U.S. foreign policy. Kennan's insights helped articulate the rationale for the Truman Doctrine, which aimed to support countries resisting communism.