But geographic reality compels Sweden to be aware of who its friends might be in moments of trouble. Some nearby countries that were not combatant powers (at first) were overrun during World War II. So Sweden arms, yes, to be able to maintain neutrality as best it can, and it also pursues an active foreign policy of making friends without making alliances with the countries that best support Sweden's cultural heritage and aspirations for freedom and prosperity.
Here in the land of the Swedish diaspora, where almost everyone knows somebody with Swedish ancestry, the local public university's law school has an exchange program with the law program at a Swedish university. I remember hearing a talk on Sweden's defense strategy given at the law school here in 1989 by a visiting Swedish professor. He, and almost everyone else in Sweden at the time, was quite concerned by repeated incursions into Swedish territorial waters by Soviet submarines on training missions. The Soviet Union and its successor state Russia have an obvious strategic interest in controlling access to harbors in Sweden, so Sweden has an obvious strategic interest in knowing whether or not Russia is planning any hostile moves. Sweden needs to be informed about the outside world to maintain its policy of armed neutrality. The cooperation described in this article is not surprising in that historical and current events context.
AFTER EDIT: I would be delighted to hear from anyone who can let me know what facts they think I have got wrong here, as the pattern of upvotes and downvotes so far suggests that someone disagrees with me, but I'm not completely sure why.