A sign that reads in Spanish: "Humanitarian aid now!" is held up during a rally in Caracas demanding Maduro's resignation. Despite weeks of sanctions, the United States hasn't been able to convince the Venezuelan leader to step down.Ariana Cubillos / AP

Two months after Juan Guaidó declared himself the legitimate president of Venezuela with the support of the United States and its regional allies, the elaborate international effort to will a new government into existence has hit a snag. Nicolás Maduro remains very much entrenched in Caracas, refusing to retire to a faraway beach, as an aide to Donald Trump once advised.

On Thursday, the old guard ominously reminded the world of that intransigence by detaining Guaidó’s chief of staff, Roberto Marrero.

Despite the many attempts to create new facts on the ground—from Guaidó’s swearing-in before roaring crowds to pro-Guaidó officials taking over Venezuelan diplomatic properties in the United States—Maduro still controls the guns in Venezuela and thus, in large part, the government. Marrero’s arrest is perhaps the biggest test yet of which side will call the other’s bluff. But given the measures the U.S. has already taken, starting with the dramatic step of recognizing Guaidó and then rapidly escalating to severe oil sanctions, its options are quickly diminishing.

The Trump administration has already deployed what U.S. officials working on Venezuela have long considered the ultimate weapon in its diplomatic and economic arsenal: imposing a de facto oil embargo on the country by redirecting revenue from Venezuelan oil sold in the United States to the opposition. (On Friday, in response to Marrero’s arrest, the Treasury Department sanctioned the state-owned Bandes bank, and four subsidiaries.)

The Trump administration has also imposed rounds of visa restrictions and sanctions on Venezuelan officials, but none of these actions have so far loosened the Maduro government’s grip on power.

In February, Guaidó traveled to Colombia to facilitate the passage of humanitarian-aid trucks over the border, and was almost entirely thwarted when Maduro’s security forces blocked bridges and clashed with protesters. Another flash point came in March, when Guaidó returned to Venezuela amid speculation that he could be arrested. He landed at the Caracas airport without incident—perhaps because a number of international diplomats were there to greet him.

As U.S. officials tell it, the latest showdown over Marrero is an act of desperation by a dictator on the ropes.

Asked how the Trump administration planned to respond, a State Department spokesperson told The Atlantic that Maduro “is betting on repression to hold on to power” and that “will not stand,” naming Venezuelan judicial and security officials who the United States believes were responsible for the arrest—a possible indicator of new targets for individual sanctions. “There will be consequences for a continued crackdown,” the spokesperson wrote in an email.

Saying that “the toughest sanctions” against the Maduro government “are yet to come,” National Security Adviser John Bolton warned on Twitter that Maduro “and his cronies will be strangled financially” if they cling to power. “The window is closing,” Bolton wrote.

Francisco Santos, the Colombian ambassador to the United States, similarly described to The Atlantic Marrero’s detention as a sign of Maduro’s “weakness” and recognition of Guaidó as a “threat.”

The envoy from Colombia, which borders Venezuela and has recognized Guaidó as president, pointed to declining support for Maduro among the urban poor, who long backed the Venezuelan leader and his predecessor, Hugo Chávez. He argued that Maduro has grown more dependent on paramilitary gangs to shore up his rule because he can’t count on the complete loyalty of the armed forces. But while some officers have publicly split with Maduro and hundreds of Venezuelan troops have fled to Colombia, the ambassador acknowledged that there has not been a rash of high-profile military defections.

“The center of gravity right now is the military, and it’s starting to peel off. What we need is a cascade. That’ll come,” Santos said.

Santos seemed unconcerned that these defections had not yet happened. “[With] a defection, you lose that chess piece; we need them there. They work better from the inside, and we need them to stay inside.

“After 20 years of destroying a country, to think that in two months [Maduro and his regime are] going to leave, it’s ridiculous. It’s naive to a certain extent,” Santos continued. “I don’t know how long it’ll take, but believe me, things are going to get a lot more tough for Maduro and his thugs.”

Yet Fernando Cutz, a former director for South America on Donald Trump’s National Security Council, sees in Marrero’s arrest not only a warning to the opposition, but also an “experiment” by Maduro to see what kind of response cracking down on lower-level opposition figures elicits at home and abroad—and thus whether the timing is right to take the next step of arresting Guaidó himself, who has already been banned from leaving the country.

The challenge for the United States in responding to Marrero’s detention is that it now has few ways to meaningfully increase the pressure on Maduro. Not retaliating, however, risks emboldening Maduro.

The U.S. could continue imposing sanctions, but their impact takes a while to be felt. For instance, the sanctions against Venezuela’s state oil company, which were announced in January, are only just beginning to bite. U.S. imports of Venezuelan crude plunged from 112,000 barrels per day to zero last week, after a grace period for companies doing business with the country. U.S. officials also say they have persuaded India, the second-largest cash-paying customer of Venezuelan crude, behind the United States, to halt purchases. (Allies such as China and Cuba receive Venezuelan oil as a form of debt repayment and don’t pay for it.)

The Trump administration could impose “secondary sanctions” on companies outside the United States that continue to buy oil from Venezuela despite U.S. sanctions, Cutz told The Atlantic, but those actions would be largely symbolic if American and Indian companies stop doing business with Caracas, leaving Venezuela with no “markets to actually sell the oil to.”

“I’m sure [the administration] can come up with” additional sanctions, Cutz said, citing as an example recent measures against the gold-mining industry, but “I don’t see a whole lot more that will be truly effective and truly revolutionary as far as Venezuela’s economy goes.”

The embargo, he added, has the United States playing a “wait-and-see game” for the next month or two to determine whether depriving the government of oil revenues will collapse Maduro’s “house of cards,” or whether Maduro manages to find other ways—including illegal mining, human trafficking, and the drug trade—to continue buying off his generals and other top officials.

“We’re basically at a point where if you want to escalate this any further, it would most likely require military actions or covert actions,” Cutz said, but the U.S., its allies in the region, and Guaidó’s would-be government have shown little appetite for military intervention despite all the tough talk, particularly from U.S. officials. Guaidó has at times hinted at supporting a foreign military intervention, but has not yet explicitly called for one. The Trump administration’s special representative for Venezuela, Elliott Abrams, stated at a recent briefing that “the military outcome is not the right outcome for the future of Venezuela” and that the U.S.’s policy “is a peaceful transition to democracy,” even as he reiterated the government line that “all options are on the table.”

“People hear the same statements over and over again [from U.S. officials]: that we’re taking names, and the world is watching, [and] there will be consequences,” without much follow-through, Cutz said. “Let’s say they arrested Guaidó today. What would we do? That’s a huge open question.

“The U.S. has made this such a huge priority and has escalated this so much, which I don't criticize—I think it’s the right approach,” Cutz said. “But what happens if change doesn’t come? What does that do to our image, what does that do to our foreign-policy priorities and foreign policy in general, to the power of our rhetoric moving forward?”

Santos said that countries could apply more economic pressure by cutting off Venezuela from aspects of the international financial system, such as the SWIFT financial-messaging network. In response to the detention of Guaidó’s aide, the countries seeking a transition of power in Venezuela should “strengthen the sanctions, strengthen the diplomatic blockade” and not be “intimidated,” he said.

The Colombian ambassador noted that his government is not advocating for negotiations with the Maduro government, because it’s following the lead of Guaidó, who has for now refused to talk with the regime he’s seeking to supplant.

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