Two years ago as lieutenant governor, Tina Smith was leading an agricultural mission from Minnesota to Cuba. A thaw in relations begun under President Barack Obama had encouraged high expectations. “I was so struck by the opportunities for Minnesota and the U.S. to build business relationships, agricultural partnerships, tourism, everything,” Smith said in an interview with an editorial writer.

But as a U.S. senator, Smith is watching those opportunities wither. President Donald Trump has flipped the script, with a series of restrictions and hot rhetoric that have made it clear he is putting Cuba firmly back in the enemy camp. Last week he turned up the pressure with fresh restrictions that dramatically limit tourist travel.

So-called people-to-people trips, which include educational and cultural group trips, are now prohibited. Trips that weren’t already booked by June 5 were likely to be rerouted to other destinations, according to the Treasury Department. U.S. cruise ships, private yachts, private planes and fishing boats are all barred from stopping at the island, and violators can be prosecuted.

Tourism to this island just 90 miles off the coast of Florida had been growing in recent years. More than 250,000 American tourists cruised or jetted to Cuba in just the first four months of this year, not including trips to visit family.

Smith called the decision to curb travel “completely misguided” and one likely to backfire. “In some ways, Cuba is the perfect trading partner for us,” she said, referring to both the nation and Minnesota, where some businesses have labored for years to develop relations that might bloom into economic activity. “By cutting off economic exchanges, we’re making it more likely that [Cubans] will move away from us, not toward us.” National Security Advisor John Bolton has labeled Cuba part of a “troika of tyranny,” and said the sanctions were designed to squeeze the island economically. Curiously, travel to Cuba for business meetings is still allowed.

It is difficult to explain why Trump would be so eager to make friends with Russia, to declare himself “in love” with North Korean dictator Kim Jong Un, to invite Philippine strongman Rodrigo Duterte to the White House, but remain so intent on crushing this small island.

Dependent, as always, on larger nations, Cuba in December signed a joint plan with China, according to Xinhua News Agency, for bilateral cooperation on a variety of fronts. Chinese companies have expressed interest in Cuba’s top foreign investment project, the Mariel Special Development Zone.

Cuba should, by any reasonable calculus, be brought into the U.S. sphere of influence. It is of strategic value to this nation, and by extension, its adversaries. A far better alternative would be to develop closer ties through trade, tourism, economic development and diplomatic relations. Failure to do so will create opportunities for countries that might be only too happy to claim an outpost so close to American shores.