A Harvard-educated conflict resolution expert is flying to Caracas next week to attempt the seemingly impossible: jumpstarting political dialogue in deeply polarized Venezuela.

The visit by Jim Tull for several days of closed-door workshops with representatives of Venezuela's socialist government and the opposition comes as the U.S. is threatening more financial sanctions and talk of military action to oust President Nicolas Maduro is swirling. Previous attempts at dialogue have failed amid bitter recriminations.

The Spanish-speaking mediator, who helped ease tensions in Venezuela following a 2002 coup against then-President Hugo Chavez, was cautious about the chances of success. The oil-rich nation is submerged in its worst economic crisis in history, with hyperinflation and shortages crushing the poor and driving masses of migrants thousands of miles from their homes.

"There's a high percentage that a lot of effort will be put into this and nothing will change on the ground," he said in an interview from Cambridge, Massachusetts. "But if you get the right people involved, and approach it step by step, then you dramatically increase the chances that something good will happen."

Tull's mission is being organized by the Boston Group, an informal network of U.S. and Venezuelan lawmakers from across the political spectrum — Democrats, Republicans, socialists and capitalists — concerned about Venezuela. The exploratory meetings were put together by Sen. Bob Corker, the Republican chairman of the U.S. Senate Foreign Relations Committee, through relationships one of his senior staffers built 15 years ago during legislative exchanges involving then-lawmaker Maduro.

Caleb McCarry, Corker's top Latin American policy aide, recently met in Caracas twice in the span of eight days with Maduro to push for dialogue, the first time, Oct. 7, accompanied by his boss. Tull's mediation effort is being called a "brainstorming round table" to distance it from failed negotiations in the past like talks led by the Vatican or one in the Dominican Republic sponsored by former Spanish President Jose Luis Rodriguez Zapatero that collapsed in February.

But it remains to be seen if a skeptical White House will endorse the initiative. The State Department and National Security Council wouldn't comment on whether they back it.

Venezuela's beleaguered opposition is divided over strategy since its boycott of presidential elections in May rallied international support but failed to weaken Maduro's grip on power. Hardliners, joined by exiled opposition leaders, say there's no point in sitting down for talks until Maduro signals he's ready to go.

"Maduro has called for farcical dialogue every time international and domestic pressure has reached a point where the country is about to change," said anti-government activist Maria Corina Machado, who was stripped of her seat in congress in 2014. "The only purpose it has served is to give more oxygen to the regime."

Other government opponents, such as former presidential candidates Henri Falcon and Henrique Capriles, favor a more moderate approach and worry the increasingly belligerent rhetoric on all sides could lead to more bloodshed.

At least publicly, the Trump administration has had no role in Corker's peacemaking effort. On the sidelines of the United Nations General Assembly, Trump joked about an August attack on Maduro in which two exploding drones sent assembled troops scattering and said action by U.S. or Venezuelan troops shouldn't be ruled out.

Still, any break from saber-rattling out of Washington could send a positive signal that the U.S. isn't pursuing just punitive measures, said Greg Weeks, a Latin American studies professor at the University of North Carolina at Charlotte.

"These below-the-surface interactions can pay enormous dividends," said Weeks. "But to gain traction, they really need some amount of support from the Trump administration."

The Boston Group backchannel has already started to bear fruit. It recently was revived after a decade hiatus to secure the release of Joshua Holt, a Utah man held for two years in a Venezuelan jail on what were widely seen as trumped-up weapons charges. Corker, accompanied by McCarry and the Boston Group's coordinator, former Venezuelan lawmaker Pedro Diaz-Blum, brought Holt home in May.

Now the retiring Tennessee Republican and his allies are looking to build on that success.

His office declined a request to comment on next week's mediation. But following his meeting with Maduro, which he described as "very good," Corker said he was looking for creative ways to break the deadlock and intended to discuss his trip with Secretary of State Mike Pompeo.

The effort led by Tull is being funded by the Norwegian Centre for Conflict Resolution, which played a major role in Colombia's peace process. It also tracks with recent calls for dialogue by the European Union's foreign policy chief Federica Mogherini.

Tull said that ideally the government and opposition will each send eight representatives comprised of a mix of Boston Group veterans and surrogates new to the workshops focused on creating a "safe space" for future dialogue but not outright negotiations — at least not for now. Among the newcomers Maduro will send is Gov. Rafael Lacava, a key intermediary in the Holt saga, and Miranda state Gov. Hector Rodriguez, according to a person familiar with the event but who spoke on the condition of anonymity for lack of authorization to discuss details.

It's still not yet clear who the opposition will send, and the country's largest anti-government movement, Justice First, which was banned earlier this year, was still debating whether or not to take part, according to two party leaders who also requested anonymity because the internal deliberations were ongoing.

Tull, whose interest in negotiation theory became very personal decades ago in Nicaragua when he was held hostage by guerrillas and negotiated his own release, said he remembers Maduro in the aftermath of the coup as a fierce advocate for his leftist views but also a good listener.

Pictures from that era show a slimmer and wide-smiling Maduro embracing then-Senator John Kerry on a New England tarmac, lounging at the Kennedy compound on Cape Cod and playing baseball with some of his fiercest opponents.

Tull is convinced that common ground can be found again but recognizes that any dialogue effort, no matter how discrete, is bound to be seen as a betrayal by many on both sides of the political divide.

"Venezuelans have been fighting for a long, long time and things just keep getting worse and worse," said Tull, "and that's not necessarily satisfactory for either side."


Follow Goodman on Twitter: www.twitter.com/apjoshgoodman