You noted differing levels of willingness for US military operations. Before NK achieved nuke status, the US had a number of decades during which if a President had truly felt a need to eliminate it's form of government, it could have done so with no military repercussions to the US homeland. Your casual remark made it sound like the US no longer had the option due to nukes, likely true. It doesn't properly represent that the US had plenty of time, opportunity and at times motive yet didn't do so, showing that not possessing a nuke, yet despite provocative actions, all it received were sanctions