Horthy gradually came to believe that his arrest had been arranged and choreographed by the Americans in order to protect him from the Russians. Indeed, the former regent reported being told that Josip Broz Tito, the new ruler of Yugoslavia, asked that Horthy be charged with complicity with the 1942 Novi Sad raid by Hungarian troops in the Bačka region of Vojvodina. Serbian historian Zvonimir Golubović has claimed that not only was Horthy aware of these genocidal massacres but had approved of them. American trial officials did not indict Horthy for war crimes. The former ambassador John Montgomery, who had some influence in Washington, also contributed to Horthy's release in Nuremberg.