There is no way to do this in democratic way, French citizens already voted against it in 2005.
https://en.m.wikipedia.org/wiki/2005_French_European_Constit...
https://en.m.wikipedia.org/wiki/2005_French_European_Constit...
Within the EU, the German army is in no condition to fight, the British is, but UK left the club, and France is entangled in Africa.
https://www.newsweek.com/germany-cant-explain-use-broomstick...
At another point literally all of their submarines were broken. They couldn't send even a single one into combat.
https://www.defensenews.com/naval/2017/10/20/all-of-germanys...