You're missing the point. NK/Iran aggressiveness isn't remotely similar to Lithuania letting Taiwan open an office.
As for how real the threat is - I'm not an expert, and I don't know you calculate threat, but NK does have nuclear weapon and it's probably the only reason why the are allowed to starve millions of human beings. They also literally, well, threatened to use it. Iran doesn't have one yet, but are lying about their status of development, enriching way more then required for civil purposes, and kicking out international watchers. Oh, and at the same time threatening to wipe Israel off the map. Saying there's no threat sounds like nitpicking to me.
