The country is still sensitive about its militaristic past, so the the 27-year-old singer jumped into a sleek slate-blue and silver catsuit which showed off her toned figure, instead of her military fatigues.
She looked like Judy Jetson from the hit cartoon series with her hair pulled back in a long pony tail.
In the video for the song, released this week, she plays an angry girlfriend who catches her boyfriend flirting with another woman, and joins the Marines to bolster her self-esteem. She goes through basic training and participates in a full-on war game.
In a hint of what was to come, Katy tweeted: “Hello Berlin! Very happy to see your electric beauty again :).”
Katy performed a high energy dance routine flanked by dancers in black PVC tops and blue pants. She flew to the floor on her knees and thrust out her pelvis as she sang the driving pop song.
Earlier, she walked the red carpet at Berlin’s Palais am Funkturm earlier in a silver metallic mini-dress, covered in white geometric pattern, like a character from “Tron.”
Katy also showed a little girl crush on Lana Del Ray, who was up for an award at the show. “Excited to see @LanaDelRey to play tonight on the Echo Awards in Germany… Blue Jeans video is tres magnifique! Congrats Yoann Lemoine!”