Because they refused to pledge allegiance to the Nazi party or serve in the military, Jehovah's Witnesses were sent to concentration camps, where they were identified by purple triangles and given the option of renouncing their faith and submitting to the state's authority. The United States Holocaust Memorial Museum estimates that between 2,700 and 3,300 were sent to the camps, where 1,400 died; in The Holocaust Encyclopedia (2001), Sybil Milton estimates that 10,000 were sent and 2,500 died. According to German historian Detlef Garbe, "no other religious movement resisted the pressure to conform to National Socialism with comparable unanimity and steadfastness."
Its historical significance makes the term Final Solution the most important example of the ability of Nazi language to integrate potentially different if not divergent approaches towards the so-called Jewish question into a conceptual frame of reference that helped facilitate systematic mass murder and to hide the Third Reich's genocidal policies behind technocratic abstractions, thus providing legitimization for perpetrators and enabling bystanders to claim not to know what was going on. Despite its inherent problems, most notably in evoking the illusion of coordinated planning and systematic implementation, the term Final Solution remains crucial for recognizing the process character of the Holocaust as a key element in a broader history of state-sponsored mass murder during the Nazi era.
Peter Hayes (How Was It Possible? A Holocaust Reader, 2015): "The Holocaust, the Nazi attempt to eradicate the Jews of Europe, has come to be regarded as the emblematic event of Twentieth Century ... Hitler's ideology depicted the Jews as uniquely dangerous to Germany and therefore uniquely destined to disappear completely from the Reich and all territories subordinate to it. The threat posted by supposedly corrupting but generally powerless Sinti and Roma was far less, and therefore addressed inconsistently in the Nazi realm. Gay men were defined as a problem only if they were German or having sex with Germans or having sex with Germans and considered 'curable' in most cases. ... Germany's murderous intent toward the handicapped inhabitants of European mental institutions ... was more comprehensive ... but here, too, implementation was uneven and life-saving exceptions permitted, especially in Western Europe. Not only were some Slavs—Slovaks, Croats, Bulgarians, some Ukrainians—allotted a favored place in Hitler's New Order, but the fate of most of the other Slavs the Nazis derided as sub-humans ... consisted of enslavement and gradual attrition, not the prompt massacre meted out to the Jews after 1941."
Ghettos were intended to be temporary until the Jews were deported to other locations, which never happened. Instead, the inhabitants were sent to extermination camps. The ghettos were, in effect, immensely crowded prisons serving as instruments of "slow, passive murder." Though the Warsaw Ghetto contained 30% of Warsaw's population, it occupied only 2.5% of the city's area, averaging over 9 people per room. Between 1940 and 1942, starvation and disease, especially typhoid, killed many in the ghettos. Over 43,000 Warsaw ghetto residents, or one in ten of the total population, died in 1941; in Theresienstadt, more than half the residents died in 1942.