Despite the supposed “air gapped” setup, I find it highly questionable to throw money at a US company for such a critical infrastructure, which will then be used behind the scenes by the US government to finance campaigns against Europe’s integrity. In addition, they are making themselves dependent on support from an American company.
Germany is a huge supporter of Open Source development with https://www.sovereign.tech/. Ministries are quite autonomous and in this case the defence ministry made a dumb decision. Doesn’t surprise me that this ministry in particular is not led by the brightest people.