After the war, Zink returned to Czechoslovakia in 1945 and joined the Czech language service of Radio Prague, the international broadcasting station operated by the Foreign Ministry. Zink's anti-Communist reports were heard by Czechs living abroad and, after the Communist Party of Czechoslovakia took power in a 1948 coup, his broadcasts became anti-government. He subsequently lost his job and went into hiding until he, his wife and two-year-old son could flee to England. He became a British subject in 1949, and rejoined the BBC and worked on its European service until 1951. He then joined NATO where he worked as a political and economic analyst until 1957.