having a low interception rate, most recently in Saudi Arabia, is a real world problem for those hoping for a preemptive strike against North Korea. They're better than nothing- inject an additional degree of uncertainty- but also can't be depended on.
Kim has probably just pulled off a classic Kim stall by agreeing to talks before the US/ROK joint exercises and buying some more time. Don't expect him to accept any deal that isn't disproportionately in his advantage.
If Russia and China mostly comply with sanctions, he probably will begin to feel some economic desperation within a year or two.
Re: Patriot missiles
Kim has probably just pulled off a classic Kim stall
That can not be true. It could never happen against your dear leader since he is a master negotiator.