President Barack Obama’s decision to pursue new relations with Cuba was driven in part by a stinging realization: Longstanding U.S. policies aimed at isolating Cuba had instead put Washington at odds with the rest of the world.

The American economic embargo on Cuba drove a wedge between the U.S. and Latin American nations. In an annual diplomatic embarrassment, the United Nations General Assembly votes overwhelmingly to condemn the U.S. policy. And while the U.S. was clinging to its economic restrictions against the small communist nation just 90 miles off its shores, leaders of China, Russia and Brazil flocked to Havana, promising millions in investment.

“Though this policy has been rooted in the best of intentions, no other nation joins us in imposing these sanctions, and it has had little effect beyond providing the Cuban government with a rationale for restrictions on its people,” Obama said Wednesday as he announced historic shifts in U.S. relations with Cuba following 18 months of secret negotiations.

The embargo itself will remain in place; only Congress can fully revoke it. But the president is moving on his own to expand economic ties, open an embassy in Havana, send high-ranking U.S. officials including Secretary of State John Kerry to visit and review Cuba’s designation as a state sponsor of terrorism. The U.S. also is easing restrictions on travel to Cuba, including for family visits, official government business and educational activities. Tourist travel remains banned.

For the president, the moves signaled his willingness to stretch his executive authority to remake American foreign policy without Congress. As he enters the waning years of his presidency, Obama is increasingly flexing his presidential powers not only on U.S.-Cuba policy, but also on immigration, Internet neutrality and climate change.

The president had hoped to revamp the U.S. relationship with Havana earlier in his tenure. But Cuba’s five-year detention of American government subcontractor Alan Gross was a persistent roadblock.

Gross was released Wednesday as part of a deal to normalize diplomatic ties that also includes a prisoner swap.

While Obama’s actions more closely align the U.S. with the rest of the world, he faces staunch political opposition from Republicans and other supporters of the embargo.

Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina said Obama was carrying out a policy of “appeasement of autocratic dictators, thugs and adversaries, diminishing America’s influence in the world.”

Sen. Marco Rubio, R-Fla., said he would seek “to unravel as many of these changes as possible.”

In an extraordinary show of coordination between longtime foes, Obama spoke to the American public Wednesday at the same time Castro was addressing his nation in Havana, where church bells rang and schoolteachers paused lessons to mark the news. Castro said that while the U.S. and Cuba remain at odds on many matters, “we should learn the art of living together in a civilized manner in spite of our differences.”

Half a century ago, the U.S. recognized Fidel Castro’s new government soon after his rebels took power from dictator Fulgencio Batista. But before long things began to sour as Cuba deepened its relationship with the Soviet Union. In 1961 the U.S. broke off diplomatic relations, and then came the failed, U.S.-sponsored Bay of Pigs invasion, meant to topple Castro. A year later a U.S. blockade forced removal of Soviet nuclear missiles from Cuba in a standoff that brought the world to the brink of nuclear war.

Over time, support for the embargo from nations friendly to the U.S. faded. For 23 years in a row, the U.N. General Assembly has voted to condemn the embargo, with Havana gaining increasing support.

The latest vote on Oct. 29 was 188-2, with only the U.S. and Israel voting “no.” General Assembly resolutions are nonbinding and unenforceable but they do reflect world opinion, and the vote has given Cuba an annual stage to demonstrate the isolation of the U.S. on the embargo.

The number of Americans who see Cuba as a serious threat has declined. A 1983 CNN/Time poll found 29 percent considered Cuba a very serious threat. That dipped to 13 percent in 1994 and 12 percent in 1997.

Jeffrey Engel, the director of the Center for Presidential History at Southern Methodist University, welcomed the policy shift but said the U.S. had been hanging on to an unsuccessful policy for far too long.

“That it took until 2014 demonstrates a fundamental flaw in American strategy employed throughout the Cold War and to this present day,” Engel said. He added that American sanctions on Cuba “bolstered the regime’s popularity at home, as anti-American sentiment was effectively used to distract suffering peoples from their government’s own flaws.”

The full impact of the policy shift agreed to by the U.S. and Cuba remains unclear and may not be known for some time. But to Obama, the result of simply staying the course is well known.

“I do not believe we can keep doing the same thing for over five decades and expect a different result,” he said.

(AP)