President Trump is pursuing a far more aggressive trade policy than he embraced in his first term, allowing his unfettered instincts about how to put America at the forefront to guide him with little pretense of investigations or extended deliberations.

Since taking office, Mr. Trump has threatened tariffs on goods from potentially every global trading partner. That includes proposals to tax more than $1.3 trillion of imports from Canada, Mexico and China — many times the volume of trade his tariffs affected in his entire first term.