Sweden became NATO’s newest member on Thursday (7 March 2024), upon depositing its instrument of accession to the North Atlantic Treaty with the Government of the United States in Washington DC. With Sweden’s accession, NATO now counts 32 countries among its members.
Something being democratic is not the only criterion, because you wouldn’t want your neighbors to vote in favor of collectively owning you as a slave, even if your vote against gets counted.
It’s just one safety measure - if a politician still would win an election after 8 years (life changes entirely in only 1 year), for example, that’s likely for wrong reasons. Like using administrative resource, pro-government mass media, crooked elites etc.