The last 3 Presidents failed to stop the North Korean dictator's nuclear binge, but the last President is most to blame.
The most important lesson I learned as a bartender was never to serve someone who arrived at your bar already drunk. If you pour just one drink for this person and they get in a car crash the blame falls squarely on you. It doesn't matter if the guy got drunk at the bar next door or if he's been barhopping all night. You were the last person to serve him before he plowed into a family of five. The other bartenders share the blame, but you were the last person who had an opportunity to prevent a tragedy.
Apply this metaphor to the past three Presidents and the North Korean dictator with the Moe Howard haircut. President Clinton freely poured liquor down Kim's father's throat after the previous dictator promised not to drink and drive. President Bush called North Korea part of an "Axis of Evil" and gave stern warnings regarding behavior, but the little dictator was still allowed to imbibe. Enter Kim Jung-un. He bellied up to the Obama administration blind stinking drunk. He received a few warnings, but was allowed to drink his fill and then some. President Obama knew Kim was a ticking time bomb (a nuclear one) when he stumbled out of the bar. The President just let him go. It was on Obama's watch that Kim perfected his nukes and finally harnessed the missile technology to deliver a bomb. Now he's driving around and threatening lives and nobody knows where he'll turn next.