Frida Ghitis, a former CNN producer and correspondent, is a world affairs columnist. She is a frequent opinion contributor to CNN and The Washington Post and a columnist for World Politics Review. The opinions expressed in this commentary are those of the author; view more opinion articles on CNN.

(CNN) The Trump administration has just announced a new tightening of sanctions against Cuba, once again showing the world that under today's leadership, America's face to the world looks relentlessly aggressive, threatening and punishing. The new restrictions affect US citizens traveling to Cuba through organized tour groups, such as some educational and cultural trips (a common way to visit the island), and ban US cruise ships from stopping in the country, the most popular way to visit.

The policy is misguided. It is true that the Cuban government oppresses its people and deprives them of many freedoms, while helping to prop up the malevolent Venezuelan regime. But America already tried imposing tight sanctions for 60 years, and Cuba's Communist Party remained thoroughly in control. The "group people-to-people educational" travel authorization that Trump is now curtailing was possibly the most effective way to bring about change, empowering Cubans while easing their suffering. Now, perhaps with an eye toward winning the 2020 vote in Florida, where many older Cuban-Americans tend to welcome hardline policies, Trump is rolling back some of the moves made by President Barack Obama.

When Obama restored relations in 2014, I was critical of the way he did it, writing that "Obama had an overwhelmingly strong hand in negotiations," but played it badly. "Badly, that is, for the sake of the Cuban people." Obama extracted almost no concessions from the regime and granted it enormous benefits.

If Obama's policy was all honey and no vinegar, Trump's foreign policy arsenal is mostly bitterness and anger. In Trump's policy, America looks like a country determined to intimidate and bully its way across the world, with little concern for human beings.

His warm words and praise are reserved for some of the world's worst tyrants. Everyone else, including friends , gets the push-around treatment.

That's not who Americans are. Millions of US citizens are remarkably kind, generous and open-minded. Indeed, one of America's greatest strengths has been its ability to inspire, to spark admiration. But instead of embodying the best of America, Trump struts on the world stage fomenting the image of a country that is cruel, selfish; his policies prompting mostly fear and contempt.

The Cuba news came as Trump represented the United States in the United Kingdom, a visit he started by insulting London Mayor Sadiq Khan, calling him a "stone cold loser." Khan had criticized Trump ahead of his arrival, but Trump, who punches back against critics, responded in a manner that would have been unthinkable with any other president of the United States. He also disparaged Meghan Markle , the American wife of a British prince, after being told she, too, had criticized him, and he lied repeatedly in a press conference and throughout the trip. Trump likes to say he's making people respect America again, but he is embarrassing the country.

On Cuba and elsewhere, his bullying style, ostentatiously devoid of diplomatic niceties, pleases his most devout followers, but so far it doesn't seem to be achieving much of anything. That's because too often it appears to be motivated by his emotion-driven impulses, like those of an insecure child, pushing and menacing real and perceived foes, rather than examining causes and setting a smart course of action.

The world is paying attention. The huge protests against him in London proved people are following the cruelties of the Trump administration. One protester, for example, carried a sign that read , "Kids in cages have heartbeats too." The reference was to the thousands of children that the administration separated from their parents at the border with Mexico, which remains one of the most shameful episodes in the history of the United States.

In his typically vindictive style, Trump has cut aid to the Central American countries from which thousands of migrant families are making their way to the US to escape violence and misery. The aid cut is all but guaranteed to add to the reasons for their departure, and worsen the crisis at the US-Mexico border.

Now, reportedly against the advice of his own advisers, Trump is threatening to impose tariffs on Mexico if it doesn't stop Central Americans headed to the United States from crossing its territory.

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Like the threats against Mexico, the move against Cuba also punishes Americans. US consumers will have to pay for any tariffs imposed on Mexican imports, and US citizens are the ones who will no longer be allowed to travel to Cuba. To punish Cuba for its lack of freedom, Trump is restricting the freedom of Americans to travel there. Visits to Cuba have been soaring. In the first four months of this year, more than 142,000 Americans stopped in Cuba on cruises. Many others flew there; commercial flights from the United States will continue to be permitted under the new restrictions, a State Department spokesperson said. Corporate and private aircraft will not.

But it is Cubans who will be the main victims of the new rules. American dollars, America culture, values, friendliness, optimism, will now be in much shorter supply in Havana and the rest of the island. Instead, the Cuban people, like the rest of the world, is seeing the face of an angry, vindictive America; not inviting or inspiring as it used to be, but angry, mean-spirited and, on top of it all, pretty inept.