[guerrilla]

I would say American lobbying and propaganda in Sweden and Finland, which we've had for decades. We were already de facto members anyway though. On the other hand, it's not like we had a choice. We voted for anti-NATO parties who, after the war started, changed their position and rejected any referendum and refused to wait until the autumn elections. Polls showed that a majority in Sweden didn't want to join if Finland didn't (and a majority did if Finland did), so you can effectively restrict your question to Finland (maybe someone else here has more details on their case.) There was a good reason for joining if Finland did though. We dismantled a lot of our military at the end the cold war and so we relied on an exclusive partnership with Finland; thus, without them, we'd be pretty weak.