Racing to prevent the collapse of their healthcare systems overwhelmed by the coronavirus pandemic, vulnerable Caribbean nations last month turned to a neighboring country in a desperate plea for help.

They didn’t look to the United States. They asked Cuba.

Over eight days the Caribbean island, which has remodeled medical cooperation into its most profitable source of revenue, sent at least 473 doctors, nurses and other healthcare workers to eight Caribbean nations in what appears to be one of the island’s largest and fastest deployments to the region in the history of its “solidarity” medical missions.

The nations’ request for the doctors happened despite early warnings from the U.S. State Department about “exploitative conditions” in the Cuban medical program that the agency has called “abusive” on Twitter.

And the operation also put on display other regional frictions, as some Caribbean officials who have been supportive of the Nicolás Maduro regime in Venezuela turned a blind eye to the fact that some of the doctors traveled in planes provided by the Venezuelan airline Conviasa, currently under U.S. sanctions.

“People are being pragmatic about it, and so what that means is if the U.S. offered help, they would take that offer too,” said Robert Maguire, retired director of the Latin American and Hemispheric Studies Program at George Washington University.

“The U.S. aid presence in the Caribbean has been pretty skimpy, compared with Venezuela, China,” Maguire added. ”This is not a surprise that the governments of the Caribbean would turn to Cuba for assistance; Cuba has a history.”

The largest groups of Cuban medical workers were sent to Jamaica (140), St. Lucia (113), and Barbados (101).

Smaller groups traveled to St. Vincent and the Grenadines (16), Antigua and Barbuda (29), Dominica (35), St. Kitts and Nevis (34) and Grenada (5). The health workers sent to Barbados and Grenada, mostly women, are nurses. Still, other countries received a combination of physicians, nurses, and technicians who are members of a Cuban “international brigade” that specializes in disaster situations and epidemics.