North-Korea has had a bunch of conventional artillery aimed at Seoul since the 50s. They've had a "we will completely fuck your shit up"-type deterrent way before nukes, which is also why they've been able to do their nuclear programme: they used their previous deterrent to develop their new one.
There was never really any other option than "ask nicely to not do that", and maybe try some covert sabotage here and there. Everyone knew that and everyone knew that everyone knew.
In Iran the situation is different, because everyone knows that they don't have any such deterrent and they will lose in any real shooting war, with fairly little options to meaningfully fight back. There is a real inventive to actual pursue diplomacy for Iran which didn't exist in North-Korea.
Also the North-Korean regime and population is of quite a different nature than Iran. By and large, the North-Korean regime just wants to be left alone and is quite isolationist. This also doesn't really apply to Iran.
There was never really any other option than "ask nicely to not do that", and maybe try some covert sabotage here and there. Everyone knew that and everyone knew that everyone knew.
In Iran the situation is different, because everyone knows that they don't have any such deterrent and they will lose in any real shooting war, with fairly little options to meaningfully fight back. There is a real inventive to actual pursue diplomacy for Iran which didn't exist in North-Korea.
Also the North-Korean regime and population is of quite a different nature than Iran. By and large, the North-Korean regime just wants to be left alone and is quite isolationist. This also doesn't really apply to Iran.