Here's a very brief (as brief as I could make it) explanation:
We all know the "stab in the back" jew meme: that started in 1918 after jewish-German citizens did everything they could to sabotage Germany's war efforts using sedition and treason to politically and economically undermine Germany from within during WW1.
German Christians were terrified those same jews (Jewish German Communist Party KPD) would attempt to recreate the Jewish Bolshevik Revolution (that resulted in the mass murder of 20 million Christian civilians in the Soviet Union) but this time in Germany.
The (((KPD))) created Antifa in 1930 and attempted a communist coup against the legitimate German government in 1933. If you Google "German communist coup 1933" you will be fed the false narrative of the "Reichstag fire" in the hope you won't research any further and learn the truth. Do a search for "the dancing israelis" and Google will show you this image from 1972.
The 1933 jew-coup failed because German Christians knew what the jews were planning because of the blatant false narratives their jew controlled mainstream news media were pushing: this is why Hitler rose to power - because the German people elected him to stop a successful communist jew-coup which would have resulted in Germany's treasury being looted and the Christian population being enslaved and starved to death.
Hitler rounded up everyone involved in the (((KPD))) coup attempt, tried them and those found guilty of treason were sentenced to serve time in prison.
This is who the "papers please" German checkpoints were looking for. They weren't looking for innocent little darling jewish girls in red dresses. They were looking for treasonous communist criminals who participated in the 1933 coup attempt.
So many jews were found guilty of treason that WW1 prison camps were refurbished to house them all.
The World Conference of Jews (jewish leaders from all over the world) were outraged that the jew-coup failed and even more outraged that the criminals were facing justice... so Samuel Untermyer (Chair of the World Conference of Jews) called an emergency meeting in July 1933 in Amsterdam.
The WCJ agreed to give Germany an ultimatum: surrender to the WCJ, remove Hitler from power and release every communist criminal jew who was incarcerated for treason. Also allow all of those jews to resume their government jobs at full pay or judaism would declare a holy war against Germany.
Hitler said, "Nein!".
Untermyer returned to America to give this historic radio broadcast where he declared a world-wide jewish holy war against Germany. Untermyer lied about jews being crucified in the streets of Berlin and demanded the world cease all trade with Germany in an attempt to starve the German people into submitting to jewish communist rule.
This is why the German Government banned jews from owning guns in 1938 and forced the yellow star on all jews over the age of six years - because German Christians demanded to know which citizens were jews who may be participating in their holy war to murder and enslave German Christians.
This was the last straw for German Christians who demanded an end to their jewish (((Rothschild))) usury central bank and a reunification with their German brothers and sisters in Austria.
Also see Kristallnacht a.k.a the Night of Broken Glass.
The World Conference of Jews a.k.a the Jew World Order shit themselves twice because they just lost two of their largest usury central banks AND the combined power of reunified Germany posed a terrible risk to their plans to steal everything and enslave everyone.
The jew needed to declare a world war to have goy slaughter each other to protect the Jew World Order's wealth and power... but nobody would fight their Christian brothers and sisters to protect the greed of jewish bankers... so they needed a salable excuse.
The jew decided to force Germany in invade Poland by rounding up every German-Polish citizen, herding them into a town named Danzig and then slowly murdering them.
Hitler was forced to invade Poland and liberate Danzig to free his German brothers and sisters from being murdered.
The jew claimed Hitler had gone mad and was invading everyone because he wanted to take over the world.
WW2 was declared by the ZOG central banker Allied Forces.
Churchill's first act was the war crime of bombing the civilian capital of Berlin to force Hitler to respond in kind. Hitler then bombed London and the jew recruited even more white Christian nations to fight and die for the Jew World Order.