As an American, I am for tariffs on China. China is not an ally, and uses currency manipulation and other highly questionable if not outright immoral practices to spur growth for Chinese companies only. The forced sharing of secrets with Chinese firms by foreign companies doing business in China is prohibitive as well, and is designed to create an unfair advantage for Chinese companies. I also believe that running an excessively large trade deficit is extremely detrimental, as it sends wealth out of the country. There is a coming crisis with automation, and serious issues about how we will provide a decent standard of living for those willing to work who may not possess advanced degrees, yet do this in a way that incentivizes positive contributions to society rather than mere laziness. There need to be more good paying jobs in this country for the underemployed and the chronically unemployed who do not count against the unemployment rate (and I'm not talking about FIREd people, since that's all of our goal someday!). China, by manipulating its currency, and providing many subhuman working conditions, is effectively undoing decades of progress by the developed world in the name of developing the market share that they have obtained to this point.
I believe that tariffs on NATO allies are downright stupid, however. Rather, these countries should be banding together to support good paying jobs, as they all face the same coming crisis which could lead to mass discontent and political and social turmoil if not settled suitably. Instead, by raising tariffs with Canada, fighting with EU countries, and trying to blame everything on Mexico, we are isolating ourselves in the world, and making joint collective action against the substandard working conditions and disruptive business environment of China impossible.