There was however a key difference between the Nazi persecutions in Germany on one hand and in the territories occupied during WWII on the other hand.

The domestic victims of Nazi regime, especially in the prewar period, had absolutely no effective outside political support. They were being molested, imprisoned, tortured and executed at a time when Europe was still at peace. There was basically no armed resistance against the Nazi regime anywhere. Even after the outbreak of WWII those living in Germany still had nowhere to run.

The occupied territories however - Poland, Soviet Union, Yugoslavia, France, Greece, Norway etc. were either "pacified" or a true war zone. Unlike Germany, the occupied territories were never under total Nazi control. There were always safe havens and there were also groups of organized resistance. In the Soviet Union and Yugoslavia in particular the resistance grew very strong in just a matter of 6 to 12 months. The resistance fighters enjoyed at least partial support of the local population. They also received support of the major combatants - the Soviet Union and the Western Allies kept supplying vital war material, weapons and ammo. Without that kind of help the resistance could not have been sustained. That's also the reason why any attempt at resistance in Germany was doomed from the very beginning.

BTW, Major Hans von Dach contributed an excellent study of guerilla warfare and counterinsurgency measures back in the 1950's, titled Total Resistance. Excellent read if you are seriously interested.