broader use of tariffs as a preferred foreign policy tool, sometimes having nothing at all to do with trade. It amounts to the US isolating itself as it attempts to take on China. Additionally, there's the constant back and forth on twitter - we're close to a resolution, then the next day we're about to slap 50% tariffs on all Chinese goods, then back again - uncertainty is the enemy of markets and the economy in general.

I don't like his approach to NATO at all. On the one hand, he questions its validity, and on the other, he insists on greater military spending. I don't necessarily mind the latter if he were consistently supportive of NATO, but stressing the alliance generally while bullying more member domestic military spending at the same time amounts to nationalism + militarism, which many would argue was the source of 2 world wars in the last century (I would argue that). Not to say it would play out the same way today, but it adds to risks of very bad outcomes.