It shows that even the face of imminent national need...they can't act decisively.

It's not imminent national need. The situation with Russia isn't on their border, and actually hasn't gone up to even a NATO border. As long as the U.S. is a member of NATO, there is no imminent direct threat to Germany's territorial integrity. If Russia had crossed into a NATO country, you would see a different threat profile - and a different reaction from Germany. As it is, it is still peacetime in the interior of the NATO area, and so all parties involved have been appropriately pursuing their defense strategy on that basis.

They're not at war. They're not on a war-time footing, and don't need to be at this stage. I'm not sure why your expectations are so far out of line with what the situation actually calls for, but this isn't an emergency for Germany. They have to do things, yes - and they have vulnerabilities and weaknesses due to their economic reliance on Russian energy, just as we have with our reliance on foreign chips and rare earths and the like. But they're not facing "imminent national need," and they're acting pretty decisively - as your observation about their huge tank order and their volte face on clean energy (telling the Greens to shove it) demonstrates.