[JumpCrisscross]

> there is the Mutual Defence Clause (article 42.7 of the Treaty [of Lisbon]

Article 42.7 “leaves more room for interpretation than one might expect for a clause in a legally binding text” [1].

If Finland and Sweden turned down NATO membership and then suffered territorial degradation, I doubt the U.S. would step in. That, in turn, might motivate EU members to exercise their opt outs or neutrality caveats, or find that all that can be done within their power is send non-lethal aid.

[1] https://ecfr.eu/publication/ambiguous-alliance-neutrality-op...

[avar]

To expand on this: It also explicitly provides for an opt-out to preserve the neutrality of countries like Sweden and Ireland, such a clause being added at their insistence.

I suspect that when the rubber hits the road nothing would happen, are Western European countries going to get into a potential nuclear exchange with Russia defending an EU member that's got a carve-out allowing them not to do the same for them?

That doesn't apply for Finland in the same way, but I'd still expect more of a "thoughts and prayers" response from the EU than anything else.

1. https://ecfr.eu/article/commentary_article_427_an_explainer5...

[orwin]

Well, I'm pretty sure Europe is capable of sending nuclear missiles that would destroy any FOB Russia set in Finland (this wouldn't trigger Russia doctrine of only using nukes to defend its territory, not its troops).

Invasion would become way to costly for a demographically challenged country.

[fsloth]

Would EU countries waste their nukes in attrition of RU troops on aligned soil? There aren't that many (by official figures). I'm guessing most countries would prefer not to escalate to nukes unless their own territory was threatened.