A trader works on the floor of the New York Stock Exchange on Friday. (Justin Lane/EPA-EFE/REX)

President Trump’s declaration that the United States will impose tariffs on goods from Mexico starting June 10 is a perfect example of why he infuriates his adversaries and confounds his friends. While perfectly defensible taken in isolation, imposing these tariffs at a time the United States needs Mexican cooperation on other pending matters makes a successful outcome on any issue less likely.

I generally support Trump’s goals of controlling our borders, reducing illegal immigration and resetting U.S. trade deals with other countries so that U.S. manufacturing is no longer hollowed out. Accomplishing any one of these things in a single term would be an accomplishment worth crowing about. The trouble with Trump is that he’s pursuing all of them simultaneously with no apparent strategy other than to cause another country pain and force it to negotiate.

That strategy is likelier to succeed if he were to pick off one country or issue at a time, focus on that and have allies to back him up. His trade war with China is a case in point. The Chinese economy is so large, and the number of countries it trades with is so vast, that bringing China to heel requires an extended, multilateral effort. Otherwise, China will simply play one developed country off another, offering sweet deals to Japan or to the European Union to counter U.S. tariffs or sanctions.

Mexico is an important player in this effort. Without Mexican cooperation on China, Beijing could agree to a trade deal with the United States and then circumvent that by signing a separate deal with Mexico. Since either NAFTA or the unratified USMCA would allow tariff-free goods to enter from Mexico, China could simply shift production to Chinese-owned factories in Mexico and get access to U.S. markets through the back door. That’s why the USMCA has a clause that allows a country to exit the agreement if another party to the treaty signs a trade deal with a “nonmarket economy” — a classification that covers China.

A normal administration would have a strategy to prioritize its goals. If winning the battle with China is a top goal, then other battles with players who can help the United States would be put aside. That means dropping current trade fights with Japan and the E.U. to enlist their aid in the standoff with China. It also means not picking a new fight with a potential ally as crucial as Mexico when the USMCA is not yet in force. Yet the administration seems incapable of understanding Strategy 101.

The same considerations apply if one prioritizes reducing immigration over restructuring trade. Mexican cooperation would surely help reduce the flow of illegal immigration into the United States, especially from countries south of Mexico that are supplying most new migrants. (Though, of course, even perfect cooperation from Mexico wouldn’t suffice to stop immigrants from coming here illegally, which would require applying serious pressure on U.S. employers to stop hiring illegal labor and using E-Verify. Trump has yet to use his bully pulpit for the demand side of the labor equation.)

No country is strong enough to take on the entire world and win. Many leaders in history have pursued such battles nonetheless, and some such as Napoleon even are able to win initial battles against great odds. But without a sense of strategy and restraint, eventually their hubris catches up with them. Defeat is the eventual outcome, and it’s often humiliating.

Trump does best when he sets a direction and then allows capable subordinates who possess these senses to carry the policy through. That’s a big reason tax reform was achieved and why none of the pending international conflicts with nations such as North Korea and Venezuela has exploded into open conflict. But even that has its limits if the man in charge keeps opening new battlefields.

I’ll take back my assessment if these tariffs result in Mexican President Andrés Manuel López Obrador meeting with Trump and signing a comprehensive deal that resolves the trade and immigration disputes. This would be yet another example of one of Trump’s high-stakes gambles paying off. But Trump, like Napoleon, might find out that one’s adversaries get wise to your tricks after a while. And when they do, they’ll start to take you to the woodshed unless the old dog learns some new tricks.

Read more:

León Krauze: Trump’s Mexico tariffs show he has no interest in solving the immigration crisis

Max Boot: Stop demonizing Mexico. Start understanding it.

The Post’s View: Trump’s huffing and puffing at the border won’t make the migration problem disappear

León Krauze: Trump’s self-defeating plan to end aid to Central America

Henry Olsen: To win the trade war, Trump needs help from a group he’s on rocky terms with