When President Obama began opening up to Cuba two years ago, reversing U.S. policy that dated back more than a half-century, he relied on executive orders that did not require the blessing of Congress.
That means President-elect Donald Trump could easily undo Obama's actions. And on the campaign trail, Trump said he would "terminate" Obama's orders that opened the way for travel and trade with Cuba, unless the U.S. could negotiate better terms.
Trump's election victory, Fidel Castro's death on Friday and the ongoing obstacles to business dealings between the two countries have all added to an air of uncertainty about what comes next.
American lawyer Peter Quinter has seen all sides of the U.S. embargo on Cuba. He used to work for U.S. Customs in Miami, enforcing trade restrictions. Now he's in the private sector, helping clients take advantage of the Obama administration's new approach, which allows business in some sectors of the Cuban economy, provided the U.S. firms receive a U.S. government license.
"In the past two weeks, actually, I have received phone calls and emails from clients saying whether or not they want to proceed with a license or not, even to file a license application. They want to wait and see," said Quinter, the head of the Customs and International Trade Law Group.
One of his clients is seeking a license to build a warehouse in Cuba to support American cruise liners that are now traveling to the island.
"If the Trump administration reverses course of what the Obama administration has done ... the U.S. company will not open a warehouse in Cuba and similar companies will no longer do business in Cuba," he said. "It will be back to the way it was, which is not good for the Cuban people or the American people."
Seeking broad support
Supporters of the Obama administration's policy were hoping that by now, they would have enough broad-based support, including backing from the business sector, for this opening to Cuba to survive a change in administration.
But John Kavulich of the U.S.-Cuba Trade and Economic Council says Cuba hasn't made that easy.
"This is a two-way relationship," he said. "The Cuban government has not done what it could have done to provide that landscape."
And he doesn't expect Fidel Castro's death to have an immediate impact on that.
"The Obama administration allowed U.S. companies to directly export to 200 categories of independent businesses in Cuba," he noted. "The Cuban government has not permitted that to happen ... and there are companies that want to have offices in Cuba and the Cuban government has not allowed that to happen."
The Obama administration could continue to issue licenses, Kavulich says, but should probably avoid a new regulatory changes. That would be a "red cape for the bull," he said, and would be quickly overturned by the incoming Trump administration.
A change in tone
Trump advisor Kellyanne Conway told NBC's Meet the Press on Sunday that the new administration won't be fooled, as she says the Obama White House was.
"We got nothing in return," she said of the U.S. opening to Cuba. "We're allowing commercial aircraft there. We pretend that we're actually doing business with the Cuban people now when, really, we're doing business with the Cuban government and the Cuban military. They still control everything."
She said Trump hasn't decided yet whether he will roll back Obama's executive orders on Cuba.
Ana Quintana, a Cuba-watcher at the conservative Heritage Foundation, believes it will take time to work through all of that. What will change immediately, she said, is the tone.
"The Obama administration's rhetoric has been conciliatory and accepting of the Castro regime. The diplomatic discourse is going to be much different," she said.
That was clear soon after Castro died on Friday night.
Obama's statement on Saturday morning took pains not to characterize the Cuban revolutionary leader, saying, "History will record and judge the enormous impact of this singular figure."
Trump, meanwhile, called Castro "a brutal dictator" whose legacy is one of "firing squads, theft ... and the denial of fundamental human rights."