CARACAS, Venezuela — Reeling from American oil sanctions, President Nicolás Maduro’s government on Tuesday fought to keep its grip on Venezuela, opening an investigation into what it called the “violent acts” of the nation’s opposition leader, freezing his assets and barring him from leaving the country.
The announcement came only hours after the Trump administration said that it had handed control of Venezuela’s bank accounts and property in the United States to the opposition leader, Juan Guaidó, hoping to give him the tools to start running the country.
It was one of Washington’s most overt attempts in decades to carry out regime change in Latin America. In recent days, the Trump administration has recognized Mr. Guaidó as Venezuela’s legitimate president and imposed sanctions to cut off Mr. Maduro’s access to a major source of the nation’s cash: oil sales in the United States.
Now the fierce struggle to shape Venezuela is entering a new, uncertain phase. For many in the capital, the only question about Washington’s aggressive bid to oust Mr. Maduro and help install an opposition-led interim government is, what took so long?
“It was about time someone took the reins of this disaster,” said Angiseth Rodriguez, 23, a student in Venezuela’s capital, Caracas. “What they’re doing is fast and necessary.”
But just across the street, a group of senior citizens waiting in line to collect their pensions worried that the Trump administration’s actions would further bankrupt their country and deepen the humanitarian crisis that has left so many starving, sick and without basic services.
“The United States has no business meddling in this,” said Aura Ramos, 59, a retiree who can barely afford blood pressure medicine. “It’s the regular people who will be affected.”
Venezuela has the world’s largest proven oil reserves. Yet the country has been devastated by an economic unraveling under Mr. Maduro that has turned pensions nearly worthless, created an acute shortage of food and medicine, and caused millions of people to flee the country.
Last week, Mr. Guaidó, the leader of the opposition-controlled National Assembly, stood before a crowd in the capital and declared himself the country’s legitimate president, promising to allow humanitarian aid to enter the country and to call for new elections. Since then, many countries that had denounced Mr. Maduro’s re-election for a second term as fraudulent have joined the United States in recognizing Mr. Guaidó as Venezuela’s legitimate leader.
But even as economists made sense of the fine print of the American sanctions — it is still unclear how much money is at stake and how it might be made available to Mr. Guaidó — some expressed fear that the nation could be plunged into anarchy. Even if an interim government had funds, it would still not have control of the country’s institutions, including the courts and the armed forces.
The new sanctions, which prohibit returning the proceeds of Venezuelan oil sales in the United States to the Maduro government, will drastically curtail his spending power. Analysts said that could turbocharge what is already the world’s worst inflation, worsen fuel shortages and compromise the state’s ability to buy and distribute food.
“It goes to the heart of what little remains of stability and the few things that remain under the government’s control,” Asdrubal Oliveros, an economist who heads the Ecoanalitica consultancy, said of the sanctions. “This makes me very nervous.”
But the opposition contends that for a country suffering from economic free-fall and increasingly authoritarian governance, this could be the path to much-needed change.
The sanctions imposed on Pdvsa, Venezuela’s state-run oil company, escalated the fight over the country’s leadership. Mr. Maduro’s attorney general, Tarek William Saab, announced that the government had opened a criminal investigation into Mr. Guaidó’s activities and intended to freeze his assets and bar him from traveling abroad.
“These acts have undermined the peace of the nation,” Mr. Saab told reporters.
John Bolton, the United States National Security Advisor, condemned that announcement and warned that there would be “serious consequences for those who attempt to subvert democracy and harm Guaidó.”
So far Mr. Maduro has not ordered the arrest of Mr. Guaidó, a step he has taken in the past to neutralize opposition leaders who posed a risk to his power.
Many opposition leaders are sanguine about the turbulence ahead, welcoming Washington’s kingmaker role in Venezuela’s political standoff as crucial to restoring democracy and starting to rebuild a nation ravaged by mismanagement under Mr. Maduro.
“The people of Venezuela have already suffered too much,” said Maria Corina Machado, an opposition leader who has long pressed the United States to take forceful action against the Maduro government. “We must cut off all the sources of financing to this criminal regime.”
While there is little doubt that American oil sanctions will be a blow to Mr. Maduro, experts said it was unclear how quickly and widely their effects would be felt.
Crude exports to the United States have fallen by half over the past six years, but the 500,000 barrels a day that Venezuela sells to America still represent 40 percent of its oil exports. Roughly 90 percent of government revenue comes from its oil exports.
Oil experts say one of Venezuela’s principal vulnerabilities is a shortage of fuel; its five refineries are working at only 20 percent capacity. Oil traders, tanker companies and insurance companies are hesitating to supply Venezuela with gasoline and other products because they fear they could be fined under the new sanctions.
“The Venezuelans are desperately short of petroleum products like gasoline,” said Robert McNally, president of Rapidan Group, an energy consulting firm. “Whether they have 10 days or 20 days of supplies, they have a problem.”
The sanctions do not ban American imports of oil but require that funds from purchases go into accounts that are not accessible to the Maduro regime. The United States plans to make them available to Mr. Guaidó’s team, which hopes to lead an effort to get humanitarian aid flowing into the country.
Administration officials estimate that the sanctions could result in export losses of $11 billion over the next year, a crippling blow for a country that already lacks hard currency to buy sufficient food and medicine. Yet some analysts believe those assessments are overblown.
“The sanctions will deal a meaningful blow to the Maduro administration’s cash flow, but the effects will not be as harsh as the United States expects,” said Paola Rodriguez-Masiu, a Venezuelan oil market analyst for Rystad Energy, a Norwegian consultancy. “The oil that Venezuela currently exports to the United States will be diverted to other countries and sold at lower prices.”
Venezuela sells 300,000 barrels a day to India and 240,000 to China, and it makes additional sales to other countries in Europe and Southeast Asia. Many countries can be expected to buy Venezuelan crude if it is offered at deeply discounted prices. Much of the oil that has been shipped to China in recent years has been earmarked for debt repayment, but Beijing has in recent years eased pressure on Venezuela for repayment.
The most painful aspect of the sanctions could be the immediate blocking of sales of American light crude oil to Venezuela, which buys about 120,000 barrels a day to blend with its heavier oil. Without it, Venezuela’s gummy production cannot easily flow through pipelines to refineries and export terminals. Without the American supply, Pdvsa will be forced to buy the light oil from African producers, which could mean longer shipping times and higher costs.
While experts and people in the energy industry were debating the implications of the sanctions, many in Venezuela seemed to know little about the measure and its potential effects. State-run media reports have characterized the sanctions as the linchpin of an American-orchestrated coup attempt, but provided little information about the measure’s possible impact.
For Blanca Urdaneta, who sells candles to parishioners outside a church in downtown Caracas, news of the escalating tensions between Venezuela and the United States just added to her worries.
“That will spark a war,” said Ms. Urdaneta, adding that she had lost faith in both Mr. Maduro and the opposition to fix the country’s problems. “And it will bring even more misery to the Venezuelan people.”