It's crazy how there wasn't really ANY desire to join NATO before Russia showed, once again, that you can not trust them. The full scale of Ukraine really was the straw that broke the camel's back.
Sweden has been using Nato standards and running occasional exercises with Nato for a while now. They didn’t want to be officially part of it because of their unique perspective on War and Peace (see Olof Palme, sending Blue helmets in Cyprus), but there wasn’t a lack of desire to join. I’d compare it to Switzerland and the EU: the de-facto alliance is obviously beneficial, but principles have kept things separated on paper.
Finland, that’s more complicated: unlike Baltic countries and the Kaliningrad exclave, they were not in the Soviet Union. That meant a lot of pressure to remain neutral, translated until last year into “Finlandization”: a refusal to take either side. That pressure ended with the Fall of the Berlin Wall, but Finland (like Sweden) saw no reason to change their official neutral position.
When Russia started to mess with Estonia, the need to ally with Nato, in particular on cyber-defense questions, became a lot more present for everyone nearby. I suspect that Finland wanted to be ready, adopt Nato standards, training, methods, etc., and pick the right moment to join officially. Like the Baltic trio, the Russian presence looms high in the East, and I’d be surprised if there were not regular overtures and unofficial promises of support. The USA and Canada care a lot about the Arctic, and it’s not hard to count the allies there.
So, I don’t think it was a major shift—like Italy changing sides at the end of WW2. It’s more a gradual rapprochement, matching Putin’s increasingly concerning policies, that hit a very good reason to accelerate. The process has been mostly political and official. Neither Sweden nor Finland had to change guns, tactics, or radio signals.
Finland realized that Finlandization does not work any more, by observing what happened to another country that tried to Finlandize for the last 3 decades: Ukraine.
They presumably meant in terms of popular opinion, which was always going to be de facto necessary to join (even if in the end it happened without a referendum). See the list of polls enumerated here:
The Swiss position on joining the EU follows a similar trajectory: the decision is negative, but that’s not because they think joining the alliance is a bad thing or that relations are strife, but because they thought, or think, that making things official would betray principles.
Maybe compare it to a couple who live together but aren’t married and are opposed to it because one of them sees it as an encroachment of religion.
Honestly I can understand the previous sentiment, joining would have come across as an act against Putin as that's how he always frames NATO. So keeping the status quo was fine for everyone. But then he showed he doesn't respect the status quo. Just my opinion of course.
