What happens to U.S.-Cuba relations amid mysterious attacks on diplomats?

JUDY WOODRUFF: What happened in Cuba remains a mystery.

We know 21 people who work at the U.S. Embassy in Havana have suffered a variety of illnesses, including hearing loss, dizziness and headaches.

Today, the State Department ordered all non-emergency embassy staff to leave the island.

Hari Sreenivasan has the story.

HARI SREENIVASAN: The order, issued by Secretary of State Rex Tillerson, says that the State Department still doesn't have a definitive answer on the cause or source of the illnesses, but described them as coming from an attack of unknown nature.

WATCH: Ailments that plagued diplomats in Cuba puzzle investigators

Joining me for more on this is Josh Lederman, the Associated Press reporter who broke today's news on this, and Maria de Los Angeles Torres, a professor of Latin American and Latino studies at the University of Illinois in Chicago. She has written about and studied Cuba and Cuban politics extensively.

Josh, let me just start with you.

The latest on this, you know, there seems to be a difference in the word choice. We're now calling it an attack. Just a week ago, we were calling these incidents.

JOSH LEDERMAN, Associated Press: That's right.

And the United States hasn't exactly explained what has changed. It was only a few days ago that they were saying, look, it's premature to say attacks because we don't know what's causing this, so how can we say that it was a deliberate attack?

Now we have pressed repeatedly to say, you're not just using this new term casually. There's an actual difference of position here in saying specific attacks. And U.S. officials say, yes, we are now confident that Americans were targeted in Havana and this was an attempt to harm them.

HARI SREENIVASAN: And, Josh, the president did say, "They did bad some stuff to us."

I'm still trying to figure out who the "they" are in this. Does the State Department or any other agency say that there was a calculated move by perhaps another country?

JOSH LEDERMAN: No, I think the president was being deliberately vague.

The State Department, the White House and other U.S. agencies have not said that, because they don't know who it is. In fact, there's a lot of reason that the U.S. officials are skeptical that this would be something that Cuba's government from a top-down way would have ordered. So, as of right now, the culprit really remains a mystery.

HARI SREENIVASAN: Ms. Torres, what happens to U.S.-Cuba relations in the short-term if 60 percent of the embassy is ordered to go home?

MARIA DE LOS ANGELES TORRES, University of Illinois: Well, I think that the secretary of state has said that diplomatic relations are still on and that this is really about a prudent, if you will, taking care of the diplomats.

I think that we will see in the coming days and weeks whether or not the conversations continue. I think the Cuban government has invited the U.S. government to help investigate this. I think the question really is this idea of "they."

I think you really hit it on the head here, because the Cuban government is not a monolith, and there are many competing factions within that government. At least three intelligence agencies are organized and often do compete with each other, and the competition has become more fierce after the death of Fidel Castro, and as we get closer to the date of Raul Castro's resignation.

All this, I think, says we should be on the ground, and not go back on the diplomatic relations.

HARI SREENIVASAN: Josh, you have also spoken to scientists who have studied this extensively.

Is there any indication that this is just spy vs. spy sort of stuff, or any sort of a new technology that could do this, given how different the — I guess the indications are from the victims?

JOSH LEDERMAN: We know one of the these are U.S. investigators are looking at is whether this was some type of new advanced espionage operation gone awry, some type of device that was intended to listen to U.S. diplomats, who are very closely watched by the Cuban government in Havana, that somehow caused unintentional harm.

However, that's just really one of the theories that they're looking at. But, as you point out, this comes in the context of Havana, Cuba, where we had exploding seashells and poison cigars and all kinds of history in larger-than-life science fiction espionage between the United States and Cuba.

HARI SREENIVASAN: Ms. Torres, the way that the United States has responded so far doesn't necessarily feel they know the Cuban government is behind this, because the two diplomats that we expelled, it wasn't a banish and never come back in the U.S. again, an action that the United States might likely take if they knew that the U.S. — or the Cuban government was behind this.

MARIA DE LOS ANGELES TORRES: Right, I think we don't know.

And I think — therefore, I think, number one, safeguarding the health of diplomats abroad, we do that all the time. We tell them to come home when there are either tornadoes or hurricanes or potential attacks, right?

When we don't, in fact, we go back and say, we should have done that. So I think that they don't know. I think that the calls today by a couple of the Florida senators saying that we should, you know, expel all the Cuban diplomats is really so shortsighted, because we don't know what's going on.

And, in fact, in any one of the likely explanations that may be going on, we should have channels of communication open with the Cuban government.

HARI SREENIVASAN: Ms. Torres, finally, the State Department also put out a warning, a travel advisory to anyone else that is coming, any U.S. citizens that are traveling.

What are the kind of repercussions of that? What does that do to tourism or business that's happening?

MARIA DE LOS ANGELES TORRES: Well, I think that tourism, remember, has already been down.

This is hurricane season, as your show has been covering so well. So I think that tourism during this time is down. I do not think that immediately it's going to necessarily bring down the numbers any further than they are. So I think it's a wait and see.

I think that the United States should take the invitation of the Cuban government to help investigate this and keep the channels open.

HARI SREENIVASAN: Josh Lederman, any of those folks that you're talking to on the ground there, are they concerned about the deterioration of the relationship?

JOSH LEDERMAN: Certainly, we know that a lot of the U.S. diplomats who are working in Havana don't want to come home, don't want the mission to be drawn down, because they see it as really important.

At the same time, the fact that the U.S. is unable to provide assurances to — either to diplomats who are working there or even to American tourists who might come and stay in hotels in Havana that they won't be attacked by incidents that could create brain damage is a real serious concern, and not one that the U.S. felt like it could take lightly in this circumstance.

HARI SREENIVASAN: All right, Josh Lederman, Maria Torres, thank you both.

MARIA DE LOS ANGELES TORRES: Thank you.

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