When the Molotov-Ribbentrop Pact was signed, Daladier responded to the public outcry by outlawing the French Communist Party, which had refused to condemn Joseph Stalin's actions. In 1939, after the German invasion of Poland he was reluctant to go to war, but did so on 4 September 1939, inaugurating the Phony War. On 6 October of that year, Hitler offered France as well as Great Britain a peace proposal. There were more than a few in the French government prepared to take Hitler up on his offer, but Daladier declared in a nationwide broadcast the next day "We took up arms against aggression. We shall not put them down until we have guarantees for a real peace and security, a security which is not threatened every six months." On 29 January 1940, in a radio address delivered to the people of France entitled The Nazi's Aim is Slavery, Daladier left little doubt about his opinion of the Germans. In his radio address he said: "For us there is more to do than merely win the war. We shall win it, but we must also win a victory far greater than that of arms. In this world of masters and slaves, which those madmen who rule at Berlin are seeking to forge, we must also save liberty and human dignity." In March 1940, Daladier resigned as Prime Minister in France, due to his failure to aid Finland's defence during the Winter War, and was replaced with Paul Reynaud. Daladier remained, however, Minister of Defence, and his antipathy to Paul Reynaud prevented Reynaud from replacing Maurice Gamelin as Supreme Commander of all French armed forces. As a result of the massive German breakthrough at Sedan, Daladier swapped ministerial offices with Reynaud, taking over the foreign ministry while Reynaud took over defence, and Gamelin was finally replaced on 19 May 1940, 9 days after the Germans began their invasion campaign on 10 May, by Maxime Weygand. Daladier fled with other members of the government to Morocco, under the impression that the government would continue in North Africa, but was arrested and tried for treason by the Vichy government during the "Riom Trial". He was kept in prison from 1940 to 1943, after which he was handed out to the Germans and deported to Buchenwald concentration camp in November 1942 and in 1943 in the Itter Castle in North Tyrol with other French high personalities until the end of World War II. After the conflict ended, Daladier was a member of the Chamber of Deputies, and an opponent of Charles de Gaulle. He was also mayor of Avignon from 1953 until 1958. He died in Paris and is buried in the famous cemetery of Père-Lachaise.