Apart from Hebrew writers, there is considerable creative productivity in Israel in other languages, notably in Yiddish. Before World War II, Warsaw, Moscow, and New York were the main centers of Yiddish activity. In Palestine there was still a certain hostility to the Yiddish language, which was felt as a challenge to the Hebrew revival. However, with World War II the whole picture changed. The European centers were liquidated by Hitler and Stalin, and the New York center declined. Immigration brought many of the leading Yiddish writers to Israel. Here the internal attitude relaxed and became friendly, in view of the Holocaust in Europe, on the one hand, and the secure position attained by Hebrew, on the other.