This week U.S. Secretary of State Marco Rubio will travel to the Caribbean, where he will visit Jamaica, Guyana and Suriname. Having already traveled to Central America and the Dominican Republic in February, this is Rubio's second trip to the hemisphere in the two months since President Donald Trump returned to the White House on Jan. 20. Trump himself has already demonstrated his new administration's focus on expanding Washington's power, influence and perhaps even territory in the Western Hemisphere. Among his first acts after taking office was to sign an executive order renaming the Gulf of Mexico as the "Gulf of America," though few besides the U.S. government's official agencies refer to it as such. And he initially threatened to take control of the Panama Canal, though that topic has receded as a focus of his attention in recent weeks. In a similar way, Trump and Rubio are bringing more bluster than substance to Caribbean policy, which is a mistake. While the region is given short shrift in terms of time and attention by all U.S. administrations, the Caribbean's current list of urgent priorities is lengthy. As a result, regional leaders are intent on making the most of Rubio's visit. They spoke multiple times last week in preparation for it, and Barbados Prime Minister Mia Mottley plans to be in Jamaica to represent all the Caribbean island nations when Rubio arrives. Arguably, climate change could be considered the region's biggest challenge. But given the Trump administration's environmental policies, arguing over that issue would be a fruitless pursuit and take away time from things that all sides can negotiate and perhaps even agree on. Next on the agenda should be Haiti, a country without an elected government where gangs continue to expand their power and territorial control, armed with weapons that mainly originate in the United States. A Kenyan-led peacekeeping mission deployed to the country continues to lack the resources necessary to make a dent in the security situation, meaning that Haiti is a continuing source of instability for the region. Yet, while Haiti is probably the second-biggest regional challenge, it too will likely not feature much in Rubio's discussions, as each island in the Caribbean has its own individual domestic concerns that may take precedence over the bigger picture. One issue many Caribbean leaders are itching to bring up is the Trump administration's crackdown - led by Rubio - on their payments to Cuba as part of Havana's longstanding practice of sending its doctors abroad as a revenue-generating development scheme. Cuban doctors are a fixture in many Caribbean countries that find the arrangement to be an affordable way to plug gaps in their own health care systems. Now the U.S. government is threatening to sanction governments that participate in the program, including visa bans to keep their leaders from entering the United States. Supporters of Havana's doctors-for-hire scheme, including several Caribbean nations, point to the fact that Cuban doctors receive excellent medical training. The doctors are sent to work in locations where medical assistance would otherwise be unavailable. Their training and focus on preventative medicine and health policy often benefits communities beyond individual doctors' visits, as does the fact that they stay with communities for months or even years, far longer than U.S. programs that bring hospital ships or medical personnel for a brief visit of a week or two. Critics of the program highlight the abuses that the doctors and their families face. Cuba pockets the revenue the program generates, while barely paying the doctors that do the work. Often, the doctors' families are held hostage back in Cuba to ensure they do not defect once they are overseas. Beyond that, the medical care is inconsistent. While some of Cuba's doctors are top-tier physicians and researchers who could practice medicine anywhere in the world, others are spies who could bar...