It killed 6 million Jews.
It killed 3 million Catholics.
It killed 3 million Orthodox.
In August, 1939, just days before the invasion of Poland, Hitler told his generals:
Genghis Khan led millions of women and children to slaughter—with premeditation and a happy heart. History sees in him solely the founder of a state. ... Our war aim does not consist in reaching certain lines, but in the physical destruction of the enemy. Accordingly, I have placed my death-head formations in readiness—for the present only in the East—with orders to them to send to death mercilessly and without compassion, men, women, and children of Polish derivation and language. Only thus shall we gain the living space (Lebensraum) which we need. Who, after all, speaks today of the annihilation of the Armenians? ... Poland will be depopulated and settled with Germans. ... As for the rest, gentlemen, the fate of Russia will be exactly the same as I am now going through with in the case of Poland.German Nazi planners had in November 1939 called for "the complete destruction" of all Poles. "All Poles", Heinrich Himmler swore, "will disappear from the world". The Polish state under German occupation was to be cleared of ethnic Poles and settled by German colonists.
Prussia and Russia had carved up and eliminated Poland in 1795. Poland was wiped off the map in that year, and did not return as a nation until the League of Nations re-created it after World War I.
The re-creation of Poland in 1918 led to constant combat between Germany and Poland, and also between Germany and Russia. Neither state wanted Poland to exist (unless they ruled it) precisely because Poland-Lithuania had dominated both Germany and Russia in the 14th and 15th centuries. Indeed, Poland-Lithuania was arguably the most powerful state in Europe during that time.
Precisely because Germany and Russia completely obliterated Poland as a political entity in 1795, both countries felt the recreation of Poland following World War I was an insult, a theft of property they had taken through military force, and a threat to their continued existence.
This is why the Germans were happy to make treaty with the Soviet Union and divide Catholic Poland up yet again at the beginning of World War II. Even though England and France had treaties with Poland that required them to go to war to assist Poland, neither country honored her obligations. It was the famous "sitzkrieg", when French and British divisions on the Western front outnumbered German divisions 5 to 1, but the two refused to move while German divisions once more obliterated Poland.
The recreation of Poland after World War I did, however, establish a precedent. When the Jewish question was raised following World War II, the re-creation of another country, Israel, out of the remains of the conquered Ottoman Empire seemed like a good idea. Look how well it had worked with Poland!
Just as the creation of Poland following World War I led to a lasting European peace, so the creation of Israel after World War II led to a lasting peace in the Middle East.
Why do I bring all this up?
Because, some Jewish groups get upset when a Catholic bishop invokes the Holocaust.
It is useful to remember that the Nazis hated the Catholic Poles just as thoroughly, their deaths were planned just as carefully, as those of the European Jews. Auschwitz killed Catholic Poles exclusively for the first 20 months of operation.
I am truly sick and tired of the Anti-Defamation League claiming the Holocaust as a peculiarly anti-Semitic event.
I'm sorry, my elder brothers in faith, the Holocaust was not all about you. You don't get to define what can and cannot be said about the Holocaust. My brother and sister Catholics were just as thoroughly targeted, went through the same tortures, died the same deaths. Catholics have a right to invoke the Holocaust, the same as you.
Stop being such narcissists, and recognize the universality of the tragedy which was the Holocaust.