To end last week, President Donald Trump upended markets, sent diplomats reeling and ignited a shudder across global economies.

All he did was open his mouth. But the damage was done.

Trump’s plan to impose tariffs on imported steel and aluminum will ripple into the heartland, a reality that could cost farmers and a wide range of businesses dearly.

Trump will levy a 25 percent tariff on steel and 10 percent on aluminum. Retaliation is expected, with agriculture being an easy target where affected countries can inflict economic wounds in response.

This “America First” approach may satiate Trump’s need to paint foreign countries, even valuable trade partners, in antagonistic terms. But it doesn’t work for most businesses and U.S. workers.

The math is wrong. U.S. steel production is not going to revert to the good ol’ days that Trump envisions. What’s more likely is that higher priced steel and aluminum will disrupt established supply chains, harming dependent industries.

Trump claims all of this is necessary for national security, as he eyes China and Russia. But neither country supplies the U.S. with high percentages of its steel or aluminum. The burn will be felt by other nations that we are more dependent upon. And they will react.

Imagine what will happen to infrastructure plans, intended to be an economic boost for the nation. Costs will skyrocket, and needed improvements to bridges, roads and more could be scaled back.

Trump’s tariffs could impact the cost of building a new terminal for Kansas City International Airport, as the price of steel needed for the project is expected to rise. And don’t forget the many local jobs tied to auto manufacturing. …

Even the cost of a cold one could climb — the beer industry is heavily dependent on aluminum.

Too often, it’s the U.S. versus everyone else in Trump’s view of global markets, rather than the more complex reality. …

Kansas Sen. Pat Roberts was right when he said Trump’s tariffs won’t go down well in farm country. As Roberts correctly noted, “These are the people who voted for the president ... and they’re not going to be happy at all about this.”

— The Kansas City Star