You need to familiarize yourself with British and especially French history if you think they didn't wage proxy wars in the Cold War era.

Do you have specific examples of them waging proxy wars with each other post 1945?

The outright wars you mention happened after decades of peace at the end of this period as the system broke down more and more post 1848.

The First Schleswig war is 1848-1851. The second is 1864. If you want to argue that the Concert only really worked until 1848 that's a viable argument, and I' agree that was a period of relatively high peace. But that's also only 33 years, about half the time between 1945 and now.

In contrast, there have been zero wars in Western Europe post-1945, whether civil wars, external wars

I thought we where talking about Europe not Western Europe. I'm sure I can pick and choose a subregion of Europe that didn't have any civil wars in that period quite easily as well.

My original statement was:

See for example Western Europe now as opposed to 150 years ago.

But it may be worth examining Europe as a whole then. Wikipedia lists if I counted correctly 52 European conflicts between 1815 and 1914. It lists 45 conflicts post 1945. That supports your viewpoint in that there's actually a higher average number of conflicts being started per a year in the post 1945 period. There's some complicating factors in that both lists have a variety of conflicts which clearly don't constitute outright wars. I'm not sure what criteria are best to use here to decide which conflicts count as wars and which don't, but an eyeball estimate looks like there are a fair number that shouldn't be called wars in both time periods.