It all starting from the other universe in a state called the American Reich (or you call it Nazi America) a large puppet empire takes the order from the Greater Nazi Reich (or Nazi Germany) in a city called New York that its the capital of Nazi America after bombing Washington DC in 1945, later in a large building called the SS headquarters

A man who appeared to be the ReichFührer of the state named John Smith was doing his job as a guard appeared from the door

Random Nazi Guard: Sir? *doing the Nazi salute* we have a problem
John Smith: what is it?
Random Nazi Guard: sir the mean 3 is... Surrendered
John smith: *started being angry* what?! By who?!
Random Nazi Guard: sir, of according to the files and dimensional computers, it said that they got surrendered by the mane 7
John Smith: write a message to the Führer of the Reich and get the ships and the army ready we'll going to invade equestria
To be continued
Disclaimer: john smith was trusted with the mean 3, king sombra and Queen chrysalis