North Korean leadership might talk a big game, but they're not stupid. If they were to actually try anything by striking first, most of the world would be against them, and they know it. So while they might say a lot of things about how they'll destroy us all, that's all it is: talk.
I believe the United States and the rest of the world should ignore North Korea. I believe that regimen is dead set on starving their population to death while brainwashing them to worship a dead leader as a God. There's nothing we can legitimately do about because China supports them.
North Korea is China's problem since the Chinese supplied the Kim regime with the technology to produce nuclear materials. Japan is also close by. The United States is far across the Pacific and needs to concentrate on things at home. If North Korea becomes belligerent, our armed forces can be there within hours from bases in Japan and South Korea.
No, the United States should not ignore North Korea. North Korea is a fascist state run by a mad man who may be nuclear powered. As such, North Korea warrants a watchful eye. Since North Korea has issued many anti-American statements, the United States would be wise to keep them under watch.
No, I do not think that the US should ignore North Korea at all, and I think that they have a lot of power, and some dangerous weapons that if they sent to the US could make such a huge tragedy that it would take decades to get over it.