The German defense budget was 46.5 bln € in 2021 [1]. The problem is not spending, the problem is the utter mismanagement in the defense ministry and military forces. I have talked to someone who did contract work for the ministry and knows their internal processes. He proposed that the first step should be to fire everyone and restaff the ministry from scratch.

[1] https://www.bundesfinanzministerium.de/Monatsberichte/2022/0... (Ctrl-F "Ausgaben des Bundes nach Aufgabenbereichen", row title "Verteidigung")