Venezuelan opposition leader Juan Guaidó, left, who many countries have recognized as the country's rightful interim ruler, and fellow opposition leader Leopoldo López address a crowd of supporters in Caracas on April 30. (Manaure Quintero/Reuters)

On Tuesday morning, Venezuelan opposition leader Juan Guaidó, recognized by many countries (including the United States) as the country’s rightful ruler, released a video from what he said was a military base. He’s shown surrounded by troops — and with a man named Leopoldo López.

López’s presence gave Guaidó's video, which he said marked “the end of usurpation” and the final chapter in his struggle to wrest power from Venezuelan President Nicolás Maduro, extra significance.

“He’s known to be more of a risk taker than any other politician of his generation,” said Dany Bahar, an Israeli and Venezuelan economist and a fellow at the Brookings Institution. “That’s why he was in jail.”

López had been under house arrest for years. In 2014, he called people to the streets to protest the government and was arrested for inciting violence. In 2015, he was found guilty and sentenced to 13 years in prison; he was then put under house arrest and close surveillance.

But on Tuesday, López said he was freed by his captors.

“I have been freed by military men of the constitution, and of President Guaidó. I’m at the La Carlota Base. We have to mobilize. It’s time to conquer freedom. Strength and Faith,” López tweeted (before Tuesday, he hadn’t tweeted in almost two years).

“The fact that he was freed this morning, and that members of the intelligence services that were guarding him and were willing to do that is very telling,” Moisés Naím, a distinguished fellow at the Carnegie Endowment for International Peace who served as Venezuela’s minister of trade and industry in the early 1990s, told The Washington Post.

Naím stressed that “it was still unfolding” but added, “At a minimum, we have — [a] main leader of the opposition and one of the important architects of Guaidó's ascent is now free.”

In 2009, López announced the formation of a new, self-described social-democratic party, Voluntad Popular, or Popular Will — Guaidó's party.

López brought in young, politically active students, Bahar said. “Guaidó is one of those students.”

“I don’t think I can compare them,” Bahar said of the self-described interim president in his mid-30s and his mentor, the political prisoner in his late 40s. “They’re more complements than substitutes.”

“I think that López is probably the person that has most influence on Guaidó,” he said. The two prominent opposition figures, according to Naím, coordinated while López was under house arrest.

Like Guaidó, López studies involved a U.S. university (in Guaidó's case, a non-degree program established with the George Washington University; in López’s, the Kennedy School at Harvard), a fact that is sometimes used by detractors.

“It’s a statement of fact, but also subtle shade, because it’s a way to signal that he’s part of the non-chavista elite, which immediately raises the ire of those who promote chavismo, including internationally,” Eric Farnsworth, vice president of the Council of the Americas and the Americas Society, wrote in an email. “It’s like saying Guaidó is U.S.-backed . . . it’s true, but is also a subtweet that seeks to delegitimize in some quarters.”

But unlike Guaidó, López has spent years under house arrest, feeding the belief some hold that the Maduro regime is afraid of him (“He is the most charismatic leader of the Venezuelan opposition,” Naím said). And López is thought to be one of the members of the opposition who, if there were free and fair elections, would be prepared to run the country (“This is my personal opinion. . . . Among the contenders to the presidency, if there were to be elections and if he were to run, he would probably be one of the candidates with one of the most preparation,” Bahar said).

López “is a natural leader of the opposition and will have a very important role in a free Venezuela,” wrote Farnsworth, who was senior adviser to the White House special envoy for the Americas in the late 1990s, adding, “His public appearance outside house arrest will galvanize the street, even beyond what Guaidó has been able to do, and shows a unified opposition to Maduro’s continued rule.”

López may galvanize the street, but he himself may have had to turn in from it: on Tuesday afternoon, he and his wife and daughter appeared to have sought refuge in the Chilean embassy in Caracas.

correction: Guaidó studied at a non-degree program established with the George Washington University, but did not, as an earlier version of this piece said, get his graduate degree from there.