How Does NATO Gain?

If Sweden joins NATO, it should be a provider of security and not just a consumer.

While as a general rule I think Sweden should join NATO, Sweden's military is so small now that if Sweden joins NATO without increasing their military capability, Sweden in NATO is just another weakly defended nation that needs to be defended.

Sweden is wealthy with the ability to build advanced weapons. A precondition for membership should be a demonstration that Sweden can defend itself and is capable of projecting power around the Baltic Sea region to help other NATO states.

Being able to find, track, and force to the surface the next Russian submarine that enters Swedish waters would be a demonstration of intent, no?

Say? Is it possible to deploy anti-sub nets by air to trap an intruder sub and prevent it from escaping to international waters?