NATO had the nerve of accepting new members who voluntarily, on their free decision applied for joining, instead of respecting Putin's view that all countries next to Russia aren't independent, don't have the right to make decisions without consulting Russia, and are generally just Russia's backyard.
Much like the West was so hostile and aggressive towards Nazi Germany in 1938, by actually taking the position that Czechoslovakia and Poland have a right to make decisions as independent nations without submitting to Germany.
So when that's the view, sure, NATO is responsible for the new "Cold War".
Seriously, to the OP: I feel Germany could do a lot more on the field of defense. Our forces are in a pitiful state. They can barely fulfil their duty of national defense in peace time. If there was a ground war, the German army could defend a front line of maybe 20-40km only. If Russia invaded in the worst case, the German army would have to fire flares, else the advancing Russians wouldn't even find them.
I'm glad we can rely on American support and defense so far, but IMO, that's a job we should be able to do on our own. Not against America, mind you, but as partners.