Because the EU does NOT want Germany to arm, remember what happened the last couple of times ?
The EU is not worried about Germany re-arming, as the world has changed dramatically since WW2 and we have much stronger bonds in Europe than we did when Nazi Germany was around.
https://en.m.wikipedia.org/wiki/List_of_wars_involving_Germa...
https://historyguy.com/How_Many_Wars_Were_Fought_Between_Fra...
https://en.wikipedia.org/wiki/List_of_wars_involving_the_Uni...
The US rearmed Germany immediately after WW2 to be a buffer against an invading USSR.
We literally put Nazis back into command as long as they were willing to fight the Russians again.
Nobody in NATO was ever afraid of a militarized Germany, except maybe Germans.