Fortunately, a country can pursue many things simultaneously, which is often more generally effective than pursuing a single thing to the detriment of all others, thanks to diminishing returns.
Where did I say about single thing: "...weapons and other more effective preventive measures..."
Looking from the other angle - should Russia attack it'll trigger article 5. Russia can not win conventional war with NATO. It is just laughable. They're not that suicidal. And if they are it'll escalate to nuclear and then the railroad will be your last worry.
Russia can however win the US dithering, western Europe being scared of cruise missile strikes while their propagandists ask if it's worth dying for a few little towns.
Without the US Navy, NATO loses any war in the Baltic Sea. If Putin thinks the US won't respect Article 5, then he'll attack anyway. And if the US Navy is annihilated in a war against China, he'll attack anyway. Finland needs all the separation from Russia it can get.
