No one, concentration camps were never and have never been stopped.
This may be a reference to Schindler, he employed Jews in his factory, but it did not keep them out of a concentration camp, when the ghetto was cleared, they went to the concentration camp with everyone else, to walk to the factory to work every day.
there was nothing wrong or illegal about concentration camps. It was what people in them did that was wrong.
There was no 'international policeman' to stop them.
The Nazi's wanted all the Jews to look alike so they wouldn't have trouble telling them apart they didn't think that the Jews were even to them so they thought to save them some hassle so they didn't have to stop everyone and ask to see there number every time they walked by!!! The Jews were prisoners in the concentration camp and the striped pajamas were the uniform for the concentration camps.
The Allies (including Britain) stopped the Nazi concentration camps and the Holocaust by invading and defeating Nazi Germany.
when Germany surrendered to the allies
The US really didn't do anything to stop the Holocaust in Europe because, it wasn't until 1944 when they had the full scale of what was happening in Europe. The Allies decide to continue the push for Berlin to stop the Holocaust that way. The main reason for this was because, they thought that if they bombed the Concentration Camps, the prisoners would be killed from the explosions. Despite this, they did bomb few parts of the Concentration Camps and train tracks but this was only due to they bombed German Factories.
the people running the camps ran away or surrendered
Most of the people sent to the concentration camps and death camps during the Holocaust were Jews. But other groups of individuals sent to the camps included homosexuals, gypsies, political opponents, those who hid and helped Jews, blacks, and resistance workers.
Because: - they had a coast line. - they had a neutral country that was willing to accept them. - Danish Jews were assimiliated. - the Germans warned them that there would be round-ups. - the Germans did not try to stop them. (it was not the Resistance that did the sumggling)
Obviously he could not protect them once they left his factory to go to the camps to sleep, but he did his best to protect them whilst they were under his care (working in his factory).
Allied troops overran Nazi positions in 1945 and liberated the camps through direct military force.
The concentration camps were an invention of the Third Reich as a place to send anyone who they considered inferior or dangerous to the Reich. Once Germany was defeated, the concentration camp system came to an end. The few survivors went to resettlement camps, and eventually picked up the threads of their lives from there.