Britain and France seem less reluctant, probably taking some pride from standing up to Hitler in 1939, and this contributing to them seeing their armed forces primarily as defensive instruments. (Disregarding their long histories as colonial powers.)
Germany's latest experience with a large army was from a time it was used offensively, with catastrophic results for Germany. Nobody argues that Germany should build up that kind of force again.
But if peaceful countries are not able to protect themselves and each other from expansionist aggressors, seeing to annex territory, the world will most likely revert to something we've not really seen since the 19th century, just this time with nukes.
And with internal strife and polarization seeming to mostly pacify the US's ability to provide protection, combined with an increasingly powerful China flexing in East Asia, Europe may have to take some of the responsibility for maintaining the strength needed to guarantee peace.
The reason why the German Army was that big was the USSR and Warsaw pact. They were supposed to check any Soviet advance long enough, preferably before the Rhine, for the bulk of the US forces to show up after being shipped over the Atlantic. It would suck if that becomes necessary again, the high level of militarization during the Cold War was decidedly not a good thing.
This means that this time, Europe need to realize they have to be able to defend against an increasingly aggressive Russia _without_ significant US support, and may even have to have strength to spare to aid vs China. In other words, countries like Germany need to have military strength at least at the level they had during the cold war to do their part in providing safety and stability to Europe.
If this doesn't happen, I think Germany must expect that more and more countries in the area develops their own nukes, as that is the only alternative way to deter a power like Russia. How will Germany feel if Poland, Hungary, Rumania, Greece and Turkey suddenly all had their own nukes?
I would be more of a fan of a pan-EU force than a return to traditional national militaries.
Personally, I don't care much whether there is a pan-EU force or national militaries (tied together by both the EU and Nato) that fills this role, but I see it is a problem if Europe lacks the strength to properly defend countries such as the Ukraine. If Putin is, through military aggression, able to eventually gain full control of the Ukrain, I expect other "leaders" with similar dispositions will try similar actions in the future.
I imagine these days it's a little better, but it's still a bit of a magnet for the hard right in germany, for all the obvious reasons.
[0] https://ctc.usma.edu/the-insider-threat-far-right-extremism-...
PS: I think in general it's germany's ongoing far-right problem that makes nationalist-adjacent careers and institutions far less attractive to normal people, so it's sort of a vicious circle.
Ignoring the context of sending troops into war is a "shitty" move, as is characterising this kind of behaviour as being of "European people" - there have been lots of non-European empires, and colonial powers where administrated by European monarchs, not European democracies (i.e. the people).
Fighting an invading empire is not building one. These semantic games are a slippery-slope argument - structures such as NATO are pretty explicit means (in theory at least) to defending against aggression without endorsing aggression.
Europe used to be full of empires waging destructive wars all over the world. After two world wars, people had had enough. The predecessors of the EU were created to tame the former empires. To make them mutually dependent and act like ordinary countries. It worked, and Western Europe has enjoyed a lifetime of peace, which is unprecedented.
We Europeans are shitty people. If you tell us that it's ok to start acting like empires again and to send troops to fight wars far away from home, the world will have more than one Putin to worry about.