"but you have to be quite ignorant if you believe that it cannot be seen as a form of aggression"
NATO is not a material threat to Russia.
NATO is a defence pact - not a cohesive military unit. NATO does not have the ability in terms of material and equipment, coordination, and certainly political backing to do such a thing, and they never have.
They have never threatened Russias borders. There is no advantage, gain or benefit from invading Russia. Nobody in the world believes that NATO could take and hold any meaningful parts of Russia.
There is a bit of legitimacy in Russia not wanting NATO on it's borders, after all, why would it want that - but I don't think it changes the equation that much.
"I wonder why he even tries to seek a justification. But anyway that should not be your concern."
Because 'hearts and minds' matter a lot. The reason European leaders are joining the fight is because there is 'net momentum' to do so. European politicians are watching the coverage, they see what is happening. They are moved.
Particularly in Ukraine - it is not a united country. They definitely know they have cultural resonance with Russia. They are not united in joining the EU. There was every possibility that Ukranians just 'kind of gave up and accepted joining Neo Russia'. Propaganda matters.
" NATO did expand in eastern Europe, quite aggressively at times. I am not sure who is driving the wedge if you deny the fact that there are now many countries in NATO east of Germany."
It's not 'aggressive' to join a defence pact.
I'm not 'denying' anything.
"Bush trying to be a strong man just like Putin tries now made him force the association with Georgia and Ukraine because of the war on terror."
No - there is no comparison. There was literally a 'war on terror'. 9/11 happened. Islamic terrorism was a global threat. The world adapted in a lot of ways to overcome that issue.
All of this is becoming moot as Ukranians are mutilating Russian forces on the ground in Ukraine, it's exposing the Russian Army as a paper tiger: bad gear, little support, poor planning, unable to mount a truly effective coordinated campaign against a fairly weak enemy.