https://www.brookings.edu/blog/up-front/2018/07/12/as-trump-twists-natos-arm-lets-run-the-math-on-defense-spending/?utm_campaign=Brookings%20Brief&utm_source=hs_email&utm_medium=email&utm_content=64421876
https://www.aspistrategist.org.au/germanys-national-security-strategy-misses-the-mark/
https://www.ifri.org/sites/default/files/atoms/files/d._puhl_vfa_33_deutschland_die_zeitenwende_und_die_zukunft_de.pdf