My knee-jerk impression is that the European countries don't have the will to deploy their military in a show of force, which is different from saying they wouldn't technically be able to defend their borders from actual force rather than creeping intimidation.

On the other hand, the US actually LIKES the show of force, and sees it as a strategic strength, to the extent that they're overjoyed to have an ally to protect as an 'excuse' to flex muscle in the region.

Do you have any evidence to go along with that claim?

I'd guess if the US could spare people and equipment, it would be moving much closer to China at the moment.

The EU has a combined GDP more than 10x that of Russia. Russia has some advantages -- having one of the world's biggest nuclear stockpiles means that they basically get to pick their conflicts, and being an arms exporter means their military R&D is in some sense subsidized by other countries, but still, that's a pretty big deficit to make up. And they have notably not picked any conflicts that the EU would find existential.

They are just set up differently. The EU doesn't have a central military, so they can't do foreign adventures very well, and as a result they don't invade places very often. But this could be seen as a good thing...