I grew up in Austria, so while we aren't bordering Russia there is no oceans between us either.

My issue with the mandatory military service is just, I do not belive that the training is actually effective. You aren't training soldiers that you can call up and expect to peform. You are artificially inflating your military number by having "reservists" that are just as effective as untrained people picked up from the street. The 6 months of training your rank-and-file soldier gets is just not helpful anymore. It might have worked 150 years ago when we were fighting with muskets and basic cannons.

Maybe the Finnish military is different and prepare you better in the 6 months. I doubt it. The more usefull training is already voluntary and comes with a longer commitment time (both in Austria and Finland). In Austria you don't even get any training after your 6 months without opting in. Finland gives you an additional 80-150 days over 50 years according to google. Which is at least a little bit usefull.

If countries with mandatory military service bump up their current active standing military by a few thousands and offer a voluntary reservists program, that would provide a military just as if not more effective as the current system. And wouldn't force thousands of people to spend months doing something they aren't interested in.

If you really think mandatory service is necessary for the security of the country, then go the way of Singapore or South Korea where the service is around 2 years. Then the people actually are trained and spend long enough time in active duty to be ready in case of a war. But again, this 6 month mandatory service is nonsense in my opinion.

In 2013 Austria had a vote to get rid of the mandatory military service. 60% were in favor of keeping it (only 52% of people voted). The main arguments of people in favor of keeping: The civil service is essential for Hospitals, Nursinghomes, Schools, etc. as "free" labor. They aren't really free because the state is paying them. The second most common argument was "I had to do it, so they should also have to do it". Which is just stupid. A very small percentage of people actually cared about the military aspect of it.