Opposition protesters look down a battle-scarred street at police and national guardsmen in Caracas May 1, 2019. (Michael Robinson Chavez/The Washington Post)

After the failure of last week’s plot to oust President Nicolás Maduro, Venezuela’s opposition and its foreign backers are debating a new approach: extending an offer to senior government and military officials to join a post-Maduro transitional government — while also heightening the threat of U.S.-led intervention.

As the political crisis here deepened Tuesday, diplomatic activity was rapidly accelerating, particularly among nations concerned over the growing U.S. drumbeat on military options.

The European Union called on the Vatican and the United Nations to join talks to defuse tensions. Canada and other nations were seeking to enlist Cuba — one of Maduro’s closest allies — in finding a peaceful solution.

The United States, in an attempt to lure more defectors, lifted sanctions Tuesday on Maduro’s spy chief, who last week broke with the socialist leader and fled the country.

In Caracas, meanwhile, Maduro’s government began to fire back. A week after opposition leader Juan Guaidó’s failed attempt to incite a military uprising — senior loyalists were said to be poised to move against Maduro — the pro-government Supreme Court charged six opposition lawmakers with treason, conspiracy and rebellion, and they were stripped of their parliamentary immunity from prosecution.

Guaidó was not among them, suggesting that Maduro is still reluctant to move against him. Guaidó declared himself interim president in January after Maduro claimed victory in elections widely seen as marred by fraud, and has been recognized as Venezuela’s rightful leader by the United States and more than 50 other countries.

Venezuela’s Latin American neighbors reiterated their opposition to U.S. military intervention in the country, an option diplomats say could undermine the regional coalition that is working to force Maduro out.

“We believe that the international community must exert pressure for Maduro’s departure as soon as possible,” Colombian Vice President Marta Lucía Ramírez said in Washington. “Time is on their side,” she said, and if Maduro lasts “a few more months, it may be forever.”

But for Colombia, she added, “the military scenario is a non-scenario.”

Marta Lucía Ramirez, Colombia's vice president, speaks May 7 in the District at the Washington Conference on the Americas. (Andrew Harrer/Bloomberg News)

Nevertheless, the still-reeling opposition was seeking to regain momentum using the new strategy of carrot — the offer to senior Maduro loyalists — and stick.

The stick: On Tuesday, the opposition-controlled National Assembly, stripped of its powers by the socialist government in 2017 but broadly recognized internationally as the nation’s only democratic institution, opened debate on rejoining the 1947 Rio Treaty, the Cold War-era pact that the Trump administration is considering as a legal basis for military intervention.

Venezuela’s socialist government in 2013 left the treaty, a NATO-like agreement anchored by the United States that allows for mutual defense. Since Washington now recognizes Guaidó as Venezuela’s president, an official request from the National Assembly to defend against “a usurper” — as Guaidó has dubbed Maduro — could trigger the pact.

Lawmakers took a first step on Tuesday, approving a measure to send reinstatement to a legislative committee for consideration. Guaidó told The Washington Post on Saturday that if the United States proposed intervention, he would take it to the assembly for a vote.

Francisco Sucre, head of the assembly’s foreign affairs committee, said Tuesday that rejoining the pact “would give us an additional and important tool to increase pressure.”

A senior Latin American diplomat noted that the Rio Treaty outlines an array of collective actions and “does not necessarily mean military intervention.”

Guaidó’s saying he would bring military action before the National Assembly for consideration means “he probably doesn’t want to pull the rug out from the United States and leave them hanging there,” said the diplomat, who spoke on the condition of anonymity about the sensitive issue.

The opposition bid to unseat Maduro last week fell apart after conspirators within the government whom Guaidó tried to lure apparently backed out. People familiar with the plot say the opposition had told senior officials, civilian and military, that they could keep their jobs in a transitional government if they forced Maduro out.

Now the opposition and foreign governments are considering whether to make those guarantees open and “official.” The opposition has offered a pledge of amnesty to military personnel who turn against Maduro, but many now think that amnesty alone will not be enough to secure his ouster.

Juan Guaidó, president of Venezuela's National Assembly, speaks May 4 in Caracas. (Michael Robinson Chavez/The Washington Post)

One option floated last week by the Lima Group, the bloc of regional powers including Argentina, Brazil, Canada, Chile and Colombia that has been pressuring Maduro to step down, is uniting behind those guarantees to give them international heft. The Lima Group is liaising with the Contact Group, including Britain, France, Germany and the European Union, which backs Guaidó but has taken a softer line against Maduro.

Maduro loyalists “will need some kind of incentive to move from supporting the regime,” said a Canadian official familiar with the talks, who spoke on the condition of anonymity to discuss internal deliberations. “There are some people we are willing to do that with, and some we would absolutely be unwilling to do that with.”

At the same time, diplomatic and other efforts were escalating. Vice President Pence, in a speech Tuesday to the Americas Society, announced that the United States was lifting all sanctions against Gen. Manuel Cristopher Figuera, the former military intelligence chief who broke last week with Maduro.

“We hope that the action that our nation is taking today will encourage others,” Pence said.

Federica Mogherini, the European Union’s foreign affairs chief, said the Contact Group would meet with the Lima organization. She said the group would also send a “high-level mission at the political level” to Caracas to discuss options for a political solution with “all parties.”

Lima Group representatives attend a teleconference last week to discuss the crisis in Venezuela. (Leonardo Fernandez/Getty Images)

The Contact Group called on the United Nations to intensify and coordinate humanitarian aid, and said it was sending its own humanitarian mission to the Venezuelan capital.

“We’ve been very clear from the beginning that we believe there should be no military attempts, from within or outside the country, to solve the crisis through military means or the use of force in any form,” Mogherini said.

Canadian Prime Minister Justin Trudeau spoke with Cuban President Miguel Díaz-Canel about Venezuela last week in a conversation that Canadian officials portrayed as more positive than they had expected. Other diplomats made clear that Canada’s outreach to Cuba was not unilateral but part of a Lima Group decision to make contact with all parties.

Venezuela provides free and subsidized oil to Cuba in exchange for the presence of 20,000 Cubans. Havana says they are doctors and teachers, while Washington and the Venezuelan opposition say they are military and intelligence agents who have kept Maduro in power.

President Trump threatened last week to impose a “full and complete embargo” on Cuba in retribution for its aid to Maduro.

Some in the Venezuelan opposition are deeply opposed to bringing Cuba to the table. But others argue that if Havana were willing — a big if, they concede — it could help broker a deal that allows select socialist officials and loyalists to remain in office.

Havana could also build bridges with the Chavistas, socialist followers of Hugo Chávez, who anointed Maduro his successor before his death in 2013.

A banner of President Nicolás Maduro hangs in the Sarria neighborhood of Caracas. (Martin Mejia/AP)

“Cuba’s inclusion is part of making our offer of guarantees credible to Maduro dissidents, as well as to dissident Chavistas who don’t support Maduro,” said an opposition official who spoke on the condition of anonymity to discuss a sensitive issue.

In his interview with The Post on Saturday, Guaidó ruled out direct talks with Maduro, but said, “We will talk to any civilian or military official willing to take steps to save Venezuela.”

Luisa Ortega Díaz, a former chief prosecutor who turned against Maduro in 2017, told The Post it was essential for Chavistas such as she to be included the talks.

“Up to now, the approaches to the armed forces and the Supreme Court have not been successful because the interlocutors have been seen as their enemies,” she said. “For any exit, I think the Venezuelans that were touched by Chavez, both at the political level but also in the streets and slums, have to be included. They have to be part of it.”

Granting Maduro loyalists substantial guarantees remains highly controversial among some in the opposition, as well as among a public that blames them for stoking one of the world’s worst humanitarian crises. Hunger and disease are spreading, and the power and water grids have collapsed, subjecting the nation to frequent blackouts and driving some to boil sewer water for drinking.

Anthony Arangure, 8, and Michael Contreras, 17, load containers to gather water in the impoverished Caracas neighborhood of Caucaquita. (Michael Robinson Chavez/The Washington Post)

Maduro is widely seen as the face of a ruling group of senior socialist officials — some of whom have been accused by the United States of drug trafficking and racketeering. One of the biggest questions facing opposition leaders is whom they can cut deals with and whom they cannot.

A minority within the opposition is arguing against allowing significant senior leaders to remain in a transitional government. Some insist that the failed uprising last week shows that bargaining with Maduro’s backers will not work — that the only way to secure the fall of the government is through U.S.-backed military action.

“You cannot [keep] criminals who have committed humanitarian crimes, you cannot have drug trafficking kingpins, or members of judicial tribes, you cannot have individuals that are part of the mafia in gold trafficking, oil trafficking and gas trafficking, or food mafias,” said María Corina Machado, an opposition conservative. “Thinking that any of these individuals would be willing to bring justice to Venezuela, simply won’t happen.”