Why did it take so long for other countries to get involved in stopping Hitler's mass genocide?

Answer 1

For several reasons. Probably the greatest reason is that much of the world (including many in Europe) were unaware of exactly what it was that the Nazi government was doing with its prisoners.

Though of course there were some who knew the truth, for the most part either they could do nothing about it on their own, could not get word out of the tightly-controlled Nazi territories to other countries, or were participating in it themselves.

Another reason (though it seems obvious) is that there was a war going on, and even if every single allied country had known that millions were being murdered within German-occupied territory, they still would have had to fight the Axis armies until they could reach them. Indeed, the full scale of the atrocities were not realised by the world at large until the Allied forces literally began stumbling across the camps.

Finally, it should be said that though there were legitimate reasons that most of the world did not know about the genocide, many countries and leaders failed to take a full stand against Hitler and his government's mistreatment of "inferiors" when they could have. Many people knew, for instance, that Jews, Roma, Poles, and other peoples were being rounded up and taken to ghettos early on in the war. Despite the fact that most could not have known that the persecutions would lead to genocide, millions of people turned a blind eye to small-scale abuses, which allowed a large blind spot in which abuses then took place on a massive scale.

Answer 2

Hitler was very powerful. Anyone who werent his race or blond hair and blue eyes were killed. And if they were blond hair and blue eyes, they would fight and kill with Adolf and the natzis or they would try to stay away from him because if they tried to stop him, they would get killed.