Yes, and that's worked out great for the Kims for almost 70 years now. We haven't exactly given them an incentive to change or reform.
It's impossible to exaggerate how badly we botched our handling of Libya in particular. After watching what happened to Gaddafi, there was literally no other option for Kim besides an all-out push to develop nuclear arms.
Iran, not being a country populated exclusively by idiots, will be doing the same.
The US simply cannot be trusted regardless of what party is at the helm, and that's a huge problem for us as well as anyone we're doing international business with.
> This means a credible nuclear deterrent is the only way to ensure the regime's survival.
If you're a criminal bully, then the only way to not get taken down by the bigger kids is to get nuclear weapons.
And US policy towards Korea has been something else?
The reason our diplomatic options are so poor now is because we have constantly failed to deliver our end of the bargain when it comes to nonproliferation in North Korea, see the Agreed Framework. Saying that they're "just crazy bullies" has always been a stupid over simplification that gets us nowhere closer to not blowing each other up.
> and the US seems to be honest about the contempt with which it views the North Korean regime
And DPRK is not? What are you even talking about? The DPRK literally uses inflammatory rhetoric about the USA all the time.
I believe that NK was untrustworthy long before the events you cite. They didn't reach a rational conclusion. They always were belligerant, untrustworthy, lying bullies.