It's hard to say anything with certainty. Obama's tariffs were 55% on Chinese tires, a much higher tariff on a much more specific product from a specific country. Bush's steel tariffs were of minimal success according to the ITC and also exempted Canada and a lot of other countries. That the EU has decided to target Harley Davidson - ergo Wisconsin - ergo Paul Ryan and Bourbon - ergo Kentucky - ergo Mitch McConnell does a pretty good job of demonstrating that most people think a little harder about this shit than Trump does. I'm sure as hell not in support of trade wars and there are certainly better ways of dealing with China's loss-leader approach to metals refining but the market is most assuredly reacting to uncertainty rather than policy... as they should.