When the Allied forces began to land in France occupied by German troops on June 6, 1944, it was a sign of hope for the whole world that peace was approaching and that Europe would be free. What actually happened then? What happened was that one criminal and his accomplices managed to seize power in Germany. And because the party ruled, legality and illegality were intertwined and often almost interchangeable, because a government run by a criminal took for itself the legal privileges of the state and its order. The order that was meant to serve justice became perverted, thus entrenching the rule of illegality and signifying a true government of lies that clouded conscience. This government of lies was served by a system of terror in which no one could be trusted.
Therefore, the whole world had to intervene to break this criminal cycle and restore freedom and law. At this moment, we are grateful that all this happened, and this gratitude is not only from the countries that were occupied by German troops and left to the plundering of Nazi terror. We Germans are also grateful because that intervention restored law and freedom to us. If there was ever a clearly just war in history, bellum istum, it was precisely this one: the Allied action benefited even those against whose country they waged war. This remark seems important to me, as it demonstrates the unsustainability of complete pacifism based on a historical event.
(Joseph Cardinal Ratzinger, Searching for Peace,
excerpt from a lecture delivered in 2004 on the occasion of the sixtieth anniversary of the Allied landings in France,
translation by Terezie Brichtová OP)