Canada

Honestly, it's only a few countries that can do much to fight things. Canada due to how critical our outputs are for them is one, though we're going to suffer a ton for the ordeal (still worth it IMO), Mexico as well for the same reasons, but the EU and China are basically it for being able to make any notable impact.

In fact, this is actually the best time for China to stand up to the US, because of their imploding economy and population (some estimates put it as low as 400million), they won't have the international power to do much in a decade, like how little influence Russia has now. Not to mention that the EU's been declining for a while now, though they feel like they might be in a resurgence since Russia kicked them in the asses before Trump started backing a dump truck of salt their way.

If this happened just a few years later, the US's relative position in the world would've been twice as strong, so we're lucky it's happening now since the rest of the world has the power to resist effectively. But thanks to Trump, all nations that have strong trade relations with the US will have no choice but to diversify in the fear of Trump doing this sort of stuff for the next four years (or more if he amends the constitution for a third term like what Putin did).

You can only feel for the little guys like the Philippines that gets their entire industries rocked by the US tidal wave when they're so poor that all they can do is beg and hope the US realizes that they're too poor to give Trump anything at all.