After Obama's opening to Cuba, security cooperation increased. But those joint efforts have been frozen under Trump — perhaps permanently.
President Donald Trump announced on Friday the reversal of several key parts of Barack Obama's normalization of relations with Cuba, which started in December 2014.
Before an enthusiastic anti-Castro crowd in Miami, Trump signed a directive that restricted Americans' ability to travel to the island, prohibited financial dealings with the Cuban military, and laid out several stipulations on which future US-Cuban negotiations would be based.
One of the four goals of Trump's police change is to "Further the national security and foreign policy interests of the United States and those of the Cuban people," according to a fact sheet distributed by the White House.
"The policy clarifies that any further improvements in the United States-Cuba relationship will depend entirely on the Cuban government’s willingness to improve the lives of the Cuban people," the fact sheet states, "including through promoting the rule of law, respecting human rights, and taking concrete steps to foster political and economic freedoms."
Trump's directive reinstates many of the restrictions that were in place prior to the Obama-led opening. But beyond limiting travel and financial dealings, Trump's reversal may limit or end recent cooperation on security issues, particularly on drug trafficking, which appears to be returning to the Caribbean in force.
While Cuba was awash in drugs prior to Castro's arrival, once he took over and imposed a hardline anti-narcotics policy, they largely disappeared.
In the wake of an incident in the late 1980s in which several Cuban officials were executed for conspiring with drug traffickers, Cuba increased its cooperation with the US to counter smuggling in the area.
Now, despite Cuba's location between major drug producers in South America and a major drug consumer in the US, the island "is not a major consumer, producer or transit point of illicit narcotics," the US State Department reported in 2016.
And over the last decade, despite political differences, Cuban and US officials have worked closely together to track and intercept drug shipments transiting the Caribbean.
According to Col. Victor Lopez Bravo of Cuba's coast guard and border patrol, Havana has notified US officials of more than 500 drug-smuggling operations over the last 10 years. Between 2003 and 2016, Cuban authorities seized or recovered more than 40 tons of marijuana, cocaine, and hashish.
"We have prevented a huge quantity of drugs from coming into the US," Bravo told CNN. The US Drug Enforcement Administration has confirmed it is exchanging information about narcotics smuggling with Cuban officials.
After Obama's opening in late 2014, drug-enforcement officials from both countries starting having meetings in Cuba and Florida regularly. Last year, they reached an agreement that allowed US and Cuban personnel pursuing drug traffickers in the area to communicate directly for the first time — cutting down on delays and giving suspected traffickers less time to flee.
That deal came as a number of incidents in the latter half of 2016 indicated that drug trafficking was swinging back to the Caribbean — a once prominent smuggling corridor that saw drug flows wither in the face of increased enforcement and the growing popularity of routes through Mexico and the Pacific.
The freeze Trump has put on dealings with the Cuban government during his review of US policy toward the island — which now looks set to endure — has thrown that cooperation into doubt.
Two meetings between Cuban security officials and their US counterparts scheduled this year have already been canceled.
"We are waiting to see if it happens," Bravo told CNN about US-Cuba meetings where law-enforcement officials discuss tactics and share intelligence.
"It's up to the United States to announce and invite us to the next meeting," he said. "We hope it happens because it really is beneficial for both countries."
The recent US-Cuba thaw hasn't only facilitated cooperation on drug trafficking.
Lt. Col. Yahanka Rodriguez, the commander of Cuba's military cybersecurity center, told NBC news this month that over the last year and half, Cuba has given the US information on at least 17 cybercrime cases involving the US.
That information has included internet addresses thought to be part of a suspected identity-theft attempt — "addresses that we traced to the United States, for both the suspected attackers and the potential victims," Rodriguez told NBC.
Cuban officials also said they'd contacted a Homeland Security Department cybersecurity team about hacking attacks on Cuban infrastructure that appeared to come from the US — though they were not aware of an any US action taken in response to such Cuban reports made in January and May this year.
For some US officials, the security concerns related to a US reversal on Cuba extend to the geopolitical sphere.
With internal strife and economic turmoil consuming Venezuela, one of Havana's main energy suppliers and trading partners has been able to provide less and less.
"[Russia] has already started trying to make up the gap in petroleum imports to Cuba that have fallen off dramatically with the chaos in Venezuela," retired Army Brig. Gen. David L. McGinnis, a member of the Consensus for American Security at the American Security Project, said on an Atlantic Council conference call this week.
Russia has also recently forgiven billions in Cuban government debt and won a bid to build a railroad on the island.
"They're in a market for products from both Russia and China, and both of those countries have the resources to provide the loans to allow them to purchase their weapons and equipment," McGinnis said.
These are not new concerns.
In 2010, nine retired generals wrote to then-House Foreign Affairs Committee Chairman Rep. Howard Berman to say that Cuba did not pose a threat to the US and to call for the travel ban to be lifted.
"Lifting the overall travel ban would extend this cultural and economic engagement and … [enhance] our security by removing unnecessary sources of discontent in a country so close to the United States," the generals wrote.
For its part, Havana has not fully embraced Russia (or China, which is Cuba's largest trading partner and the largest holder of its foreign debt).
According to McGinnis, that is likely because of the Cuban government "wanting to have a balanced foreign policy to the best extent they can, hoping that we will step forward and do the right thing."
This isn't a return to the Cold War, but the Cuban mood may quickly change if avenues for engagement with the US appear to be closed.
"If we would step back, that would kind of take the hope away from the Cuban government that there was going to be rapprochement," the retired general said, "and obviously they would be forced toward the two eager adversaries of the United States in our own backyard."