The pressure on Maduro goes beyond diplomatic jostling. The U.S. has ended its purchase of Venezuelan oil, the government's biggest source of revenue. Some 3m Venezuelans have fled, creating a refugee crisis for its neighbours, especially Colombia and Brazil. Massive street demonstrations have presented a steady picture of citizen rage. The only significant country pledging backing for the regime is Russia.
As with Assad eight years ago, it's hard to find an analyst or Western official predicting Maduro's long-term survival.
The parallels are striking, including the way the Syrian revolt of 2011 and the anti-Maduro moves of recent weeks fit into significant historical trends.
Assad's authoritarian rule was challenged within weeks of the forced departures of two long-time Arab dictators pushed out by street protests – Zine El Abidine Ben Ali of Tunisia and Hosni Mubarak of Egypt. Libya's Muammar Gaddafi wasn't far behind. That led analysts to assume Assad was next.
'So far so good'
In Latin America, a slew of leftist populist governments like Venezuela's has been rapidly replaced through elections by pro-market conservatives. These include Brazil, Peru, Chile and Argentina. How can a holdout like Maduro survive?
Most analysts still say he can't.
"When I think about Maduro, I'm reminded of the guy who jumped off a 15-story building," noted Aaron David Miller, who worked on Middle East peace at the State Department and is now at the Wilson Center, a Washington think tank. "As he passed the eighth floor, he was asked how he was doing and replied, 'So far so good."'
The differences between Maduro's and Assad's situations are more important than the similarities, Miller said, making it hard to see Maduro surviving in power.
Fatal economics
Unlike Syria, the Venezuelan state relies for income almost exclusively on oil sales, especially to the US, and Washington's recently announced boycott could prove crippling. Second, the loyalty of the security establishment in Syria is based on membership in the Alawite minority of the Assad family, whereas in Venezuela it's more transactional; peeling away top generals in Caracas will prove easier.
Finally, the Syrian opposition is divided by tribe, ethnicity and religion with no clear leadership; in Venezuela, the opposition is famously splintered but along political lines. In the past month it has lined up behind Guaido.
In Syria, many have been more afraid of the opposition, much of it Islamist, than of Assad, said Vali Nasr, dean of the School of Advanced International Studies at John Hopkins University. Venezuela looks more like Egypt in 2011 than Syria, he said.
Dany Bahar, a Venezuelan political scientist at the Brookings Institution in Washington, said the economics of Venezuela will likely prove fatal to Maduro.
"He can't stabilize the economy, it's going to get worse and worse," Bahar said. "Half a million barrels of oil exported to the US is the only cash-generating exports he has."
