You don't know what you're talking about.
Diplomacy is the only thing that has ever led to any progress with North Korea. China is begging for it. South Korea is begging for it. Japan is begging for it - though none of this is ever emphasized in the press here.
But the US has totally given up on diplomacy since the Bush administration, which scuppered the very real progress Clinton had made (having first tried and failed to devise a military solution), with vague promises to "do something" more assertive. Obama largely pursued the same policy, after having issued the same vague and ultimately meaning promises.
And now here we are, too late to really bargain anymore, since they already have what they've long been pursuing - the only surefire way, in light of Hussein, Gaddafi, and almost 75 years of US-sponsored coups around the world, to be left alone. With Donald Trump's small fingers at the trigger.
You should try reading about this some time. Bruce Cummings would be a great place to start.