Wanamaker subsequently made a name for himself as an actor, director and producer of Shakespeare and contemporary fare on the British stage and founded the Globe Playhouse Trust. He returned to the USA in 1961 and resumed his screen career with notable performances as the Russian agent in "The Spy Who Came in From the Cold" (1965), as Moses Weiss in TV's "Holocaust" (1978) and ironically as a lawyer who tries to convince his clients to name names to HUAC in Irwin Winkler's Hollywood blacklist drama, "Guilty By Suspicion" (1991).
A veteran director for stage and TV ("The Defenders", "Columbo", "Hart to Hart"), Wanamaker's occasional directorial outings for film yielded mostly unexceptional results.