Republican presidential hopeful Donald Trump is fond of bragging that he didn’t start a war during his first stint in the White House, but if he follows through on his threat to hike tariffs to levels not seen in nearly a century, he risks sparking a massive trade war that could be devastating — not only for the global economy, but for the entire free world.

Trump’s first term saw him use tariffs, or the threat thereof, to gain trade concessions from his allies, but his main target was the People’s Republic of China, which the president correctly recognized as a fascist dictatorship intent on using its economic muscle to further its geopolitical goals long before most world leaders.