Donald Trump is the first US president since the 1930s to reject the assumption that global leadership serves the US national interest. With today’s imposition of steel tariffs on the EU, Canada, and Mexico, he’s also taking a whole new approach to conflict.

Three quick thoughts:

1. When headed into a fight, US presidents are traditionally quick to highlight the number and reliability of US allies, in part to reassure American voters that friendly governments agree on the need to fight and will share the costs and risks that fight entails. Trump, by contrast, wants Americans (and the world) to know that “friends are for snowflakes.”
2. As Republican Senator Ben Sasse noted on Thursday, Trump is using the same tool — steel and aluminum tariffs — against US allies that he’s using against China, a strategic competitor.
3. He’s ready to go toe-to-toe on trade with Europe, China, Canada, Mexico, and others simultaneously.

Is he right? Will this bold approach to putting America first benefit American workers and the US economy? We’re about to find out.