stylistic:style_transfer, quality:correction, structural:reformatting
"Ostpolitik" and Eastern Europe

In international affairs, his "Ostpolitik" engaged in dialogue with the Communist countries of Eastern Europe. He worked to reconcile the Vatican with the Russian Orthodox Church to settle tensions between the local churches. The Second Vatican Council did not condemn Communism and did not even mention it, in what some have called a secret agreement between the Holy See and the Soviet Union. In Pacem in terris, John XXIII also sought to prevent nuclear war and tried to improve relations between the Soviet Union and the United States. He began a policy of dialogue with Soviet leaders in order to seek conditions in which Eastern Catholics could find relief from persecution.