The German Ministry of Finance has already presented a roadmap on how to escalate spending to the newly (to be) agreed 3.5% target.
It's planned for Germany to reach that target by 2029 already (instead of 2035 as will apparently be agreed), with defence-related expenditure for 2025-2029 accumulating to 600 billion Euro. 2029 defence-related expenditure is planned to be 167.8 billion at 3.5% of the projected GDP with an average GDP growth rate of 2.9% annually.
- 527.7 billion within that is planned for the Bundeswehr, ramping up from 75.1 billion in 2025 to 152.8 billion in 2029.
- 42.3 billion within that is planned for "aid to illegally attacked states", i.e. for military aid to Ukraine (from 2026 on set to a static 8.5b annually). Small note here: This is direct military aid financed by the German government, not credit arrangements or other financial aid.
- 29.8 billion within that is planned for civil protection, intelligence services and IT security.
The numbers are fairly massaged to end up at that 600 billion total. Especially that 29.8 billion number is massively understated to reach that target, considering the relevant authorities have announced required investment that's easily twice what's accomodated; also the IT security investment accomodated for dips downwards in 2029, a clear indication they had to get to a mandated figure.
About 378.1 billion of the 600 billion is planned to be financed through debts made possible through a change of the constitution befiore the current parliament came into power. Overall the planned expenditure presented is about 20% of the German federal budget for the same period.