What worried Kubrick the most was that "Fail Safe" boasted the acclaimed director Sidney Lumet and the first-rate dramatic actors Henry Fonda as the American president and Walter Matthau as the advisor to the Pentagon, Professor Groeteschele. Kubrick decided to throw a legal wrench into "Fail Safe"s production gears. Lumet recalled in the documentary "Inside the Making of Dr. Strangelove": "We started casting. Fonda was already set ... which of course meant a big commitment in terms of money. I was set, Walter the screenwriter was set ... And suddenly, this lawsuit arrived, filed by Stanley Kubrick and Columbia Pictures."