When many goverment bodies more or less have to use foreign software-infrastructure, then "maginot lines" sound reasonable.

Very reasonable indeed IMO if e.g. German police has to use AWS because of lack of alternatives, or the countless local authorities running on windows.

On the other hand, it is not the US to blame for their tech-supremacy. It is Germany and France to blame.

There might be many reasons to cite why we lack behind. But the whole spirit behind a government-google, a government-aws, government-yaddayadda comes across as being more part of the problem than part of the solution.

I am personally very cynical about sovereignty as a concept - it just means "nobody is willing to try to pay the heavy price to try to stop us" dressed up as something noble. Every whinge about loss of sovereignty is a complaint that they cannot control others anymore.

While there may be some good for avoiding outside control it is a cover for their drooling about shoving others inside their domain of control.