The best possible thing it can do is to give Trump something to chest thump over on the campaign trail. The best possible real world result will IMO be none or close to none (forgetting about all the short term market volatility it seems to have ignited). Just a political football that never got to the point of materiality, but maybe forces some sort of concessions out of China.

Beyond that I think there is only downside risk. If it escalates enough I think it could derail a fairly healthy global economy and bring on the next recession earlier than necessary. Just look at the UK - nationwide businesses across the spectrum predict payroll cuts. Brexit was like taking a gun and aiming at yourself with a random targeting device, which over time will focus aim on the foot, the head, or anywhere in between. Time will tell. Trump's tariffs are similar.

As is nationalism globally. If it really takes hold, we'll be lucky if the worst impact is only global recession. Nations that trade with each other tend not to go to war against each other, and everything from Trumpism to Brexit to nationalism in Europe and beyond is about killing trade. Combine that with growing authoritarianism, especially in China and Russia, not to mention all the recent hawkish turns in our WH, and the world could become a much more dangerous place in a hurry.

Hopefully, NK will really play ball and work against that, but I think the world generally is moving in ominous directions.