North Korea, as we know it today, would not exist if not for the US and Russia using the Korean peninsula as one of the many pawns on the Cold War political chessboard. it is a problem we helped create. I have no problems with trying to clean up our mess in a non-violent way. The problem is that the only nation capable of exerting any non-violent pressure is probably China. China, a country that is also a known human rights violator, but also a fast growing country that will likely soon top the world in GDP and market size. Notice, when push comes the shove the US looks the other way when it comes to China.
No, I think the US should concentrate on settting an example of being a nation that believes in human rights and justice. That way, when we go talking shit to other nations, they can't flip to any domestic US news story, laugh, and call bullshit on us.