The decision may be disappointing, but it shouldn’t be tough for Carnival Corp., now engulfed in a public-relations nightmare over its maiden cruise to Cuba.

Now that it knows Cuban-born Americans would be forbidden from disembarking, Carnival should cancel its weeklong May 1 voyage to Cuba, the first by an American cruise line.

Indeed, until Cuba changes its long-standing policy of prohibiting native-born Cuban-Americans from arriving by sea, all American cruise lines, ferry operators and shipping companies should collectively call a time-out on plans to sail to Cuba.

It is not OK for an American business to abide by policies that discriminate against Americans. It is not OK for an American business to check the birthplace on citizens’ passports before letting them aboard. It is not OK for an American business to create two classifications of Americans, no matter the rhetoric of presidential candidates.

Upon receiving permission to launch cruises to Cuba two weeks ago, Carnival had expected the Castro government would lift its restriction on Cuban-born Americans who arrive by sea, as it has for those who arrive by air. Now, the company is trying to negotiate the policy change.

But it sounds to us like Carnival, in charting a new business frontier, is most focused on being first in the market. And to be first to Havana, it’s submitting to a communist dictator who wants to stick it to Cuban-Americans.

One of those discriminated against is Miami Herald columnist Fabiola Santiago, who was born in Cuba and tried to buy a ticket on the Fathom-brand ship that will be Carnival’s first to cruise to Cuba. Once Santiago told the travel agent she’d been born on the island, she was told Cuban law prohibited her from entering and that “Fathom cannot accommodate Cuban-born individuals.”

“Something precious is lost when a foreign government dictates what kinds of U.S. citizens can sail out of the Port of Miami,” Santiago wrote.

We stand with Santiago — and all Cuban-Americans — appalled to learn Carnival is putting its business goals ahead of its commitment to good corporate citizenship. We similarly call on the other cruise companies, standing in line to sail to Cuba, to similarly refuse to accept discrimination against Americans based on where they were born.

For those of us who have supported President Obama’s decision to re-engage Cuba after 54 years of failed policies, it’s again disappointing that Raul Castro refuses to move more quickly in breaking down even small barriers, like this one. Instead, it’s feared protests over this policy — and editorials like this one — will cause Castro to dig in his heels.

In this moment, we’re reminded of something President Obama said during his historic trip to Cuba last month.

“In the United States, we have a clear monument to what the Cuban people can build: It’s called Miami.”

Miami is a great city in large part because of many great contributions by Cuban-Americans.

A good number of our Cuban-born neighbors may never want to visit the island until it embraces real democratic change, but that should be their choice.

Unless Cuba accepts all Americans who’d like to cruise there, Carnival should table the launch of its inaugural cruise to Cuba.

To show support for our fellow Americans, other citizens booked on this cruise might similarly want to reconsider their plans.

— Sun Sentinel (Fla.)