After more than three weeks of mass anti-government protests on the streets of Caracas the battle for Venezuelan democracy has turned into a war of attrition.
Who can hold out longest - the demonstrators demanding elections and the removal of hardline socialist President Nicolas Maduro, or the National Guard riot troops protecting him?
Demonstrators took to the streets on Wednesday for the latest protest hoping to match an April 19 march that drew over a million supporters.
"If these people squeeze, the man won't last three more days," a colonel in Venezuela's military intelligence (DGIM), told Univision in a voice message over the weekend. Asking to remain anonymous, he added, "The police and the National Guard are exhausted from putting up with this crap," he added, saying the troops were going hungry and desertions had occured in some units.
Maduro, and his predecessor, Hugo Chavez, were able to survive several previous threats to their so-called Bolivarian Revolution thanks in large part to fierce political and violent repression of street protests. They were also aided by a divided opposition and a broad degree of socialist solidarity from allies in Latin America, led by Cuba.
But analysts say the tables have turned, making the current crisis more unpredictable.
"It's a crisis with a number of different aspects. Maduro is in much bigger trouble," said Phil Gunson, Andean regional analyst for the International Crisis Group, who has been based in Caracas since 1999.
Gunson and others point to a united opposition and intense international pressure from the Organization of American States (OAS) for a restoration of democracy and separation of powers in Venezuela.
"It does seem that the government is entering a phase, you might call it the endgame. This is a regime that has lost its forward momentum, it's going nowhere," he said.
Few experts are willing to declare Maduro a dead duck, but all agree he is running out of options. "Let's say the regime has huge cracks and so at any point you could have an earthquake," said Javier Corrales, a political science professor at Amherst College in Massachusetts. "That doesn't means it's inevitable or that it's going to happen tomorrow."
Among the keys to Maduro's future are the loyalty of Venezuela's military top brass and the role of Cuba, which has scores of agents in Venezuela advising the government on everything from economic policy to national security and counter-intelligence.
Cuba's economy is heavily dependent on Venezuelan oil shipments at preferential rates.
Chavez, a charismatic former military officer, cemented his power by seeking to politicize the armed forces, appointing ideologically sympathetic generals to important government positions. Some senior officers have been accused of corruption, including drug trafficking and money laundering charges in the United States.
"For anyone involved in illicit activity a transfer of power is a threat to their livelihood," said Corrales. "And any suggestion they might get called to account for their actions is a big, big problem."
The latest crisis has shaken the confidence of the military, according to three senior officers who reached out to Univision via an intermediary. They worry about the staying power of the National Guard riot troops after so many days of demonstrations.
"The ones who they send out to the demonstrations don't get food or an allowance. They send them out there and they go all day hungry. They can't go on repressing the people like that," said the DGIM colonel.
On one recent evening, demonstrators projected the words "National Guard, aren't you hungry?" in large letters onto the facade of a Caracas apartment building.
He said two captains and four colonels had been arrested for failure to obey orders, while three others, a captain and two lieutenants, deserted in Colombia.
The military are not going to help out the National Guard, he added. "The army's job is not to go out on the street and confront the population. They are not going to massacre the people," he added.
The latest crisis has cost more than a dozen lives with scores more injured in shootings and daily clashes in cities around the country between rock throwing protesters and security forces armed with rubber bullets and tear gas. Another 10 people also died during night-time looting last week.
The opposition is demanding long overdue elections and the restoration of constitutional order after the government-dominated Supreme Court blocked legislation passed by the opposition-controlled National Assembly.
Over the last year, Maduro has outraged opponents and the international community by jailing opposition members, or banning them from holding office, and indefinitely postponing local and state elections.
This month's turmoil is Venezuela's worst since 2014 when 43 people died in weeks of protests.
Maduro said over the weekend that he wouldn't give in to opponents and again urged them to rejoin negotiations they broke off in December.
But opposition leaders say they have no plans to meet with Maduro and are demanding the immediate scheduling of elections.
The latest crisis began when the Supreme Court briefly assumed the powers of the opposition-controlled National Assembly. The court quickly reversed course, but the unconstitutional move provided a new spark for public outrage.
Corrales compared it to other uprisings like the Arab Spring and the color revolution in eastern Europe a decade ago. "They were triggered by electoral expectations," he said noting that there is plenty of historical evidence that repressive governments are undone when they mess too much with the electoral process.
"That is volatile," he added.
Protesters are also angry over shortages of medicines, food and other goods as well as unaffordable prices for many basic items due to runaway hyperinflation. Venezuela, an oil-rich nation of 30 million people, has the world's largest reserves of oil and gas and has seen its economy fall apart in the last four years largely due to falling oil prices and what analysts describe as irresponsible government spending and rampant corruption.
"People are desperate. This humanitarian crisis has driven people onto the streets," said Gunson.
This week protests continued. On Monday thousands shut down the main highway in Caracas, some organizing picnics, reading books and reclining under umbrellas they brought to protect against the blazing Caribbean sun.
"The side that gives up is the side that loses," said retired professor Lisbeth Colina. "We must remain in the streets. I'm not scared of the repression they're throwing at us," she said.