BOGOTÁ, Colombia — When the leader of Venezuela’s opposition landed in Caracas this week following a world tour meant to drum up support for regime change, his country’s authoritarian ruler handed him neither an arrest, which would have galvanized supporters, nor the chance for a hero’s welcome at the airport.
Instead, President Nicolás Maduro appeared to greet his rival, Juan Guaidó, with the same policy of slow strangulation that has drained the opposition of much of its momentum over the past year, cracking down on his movement enough to wear down its members, but without going so far as to spur the world to action.
Moments before Mr. Guaidó arrived, Mr. Maduro’s supporters attacked journalists who were there to cover his arrival, punching them and dragging at least one woman by the hair. Once Mr. Guaidó landed, government backers chased him out of the airport, cutting off any plans he had to make a speech, and then attacked his car with traffic cones and at least one metal pole.
And as Mr. Guaidó slipped through, authorities arrested his uncle, accusing him, without presenting evidence, of bringing explosives into the country.
Hours later, Mr. Guaidó stood with a few hundred supporters in a plaza in an opposition stronghold in eastern Caracas and declared victory.
“I defied the dictatorship and I entered the country,” he said. “Venezuela is going to be democratic and free.”
Mr. Guaidó also said he would be announcing the creation of a “Venezuela Fund,” a multilateral program meant to help the country recover from its long and devastating economic crisis.
But he offered no other plan to remove Mr. Maduro. That, along with his chaotic arrival and the growing frustration among his base caused by the glacial pace of change, spoke eloquently about the challenges Mr. Guaidó is facing at home.
On Tuesday, as Mr. Guaidó arrived in Venezuela’s capital, Caracas, Mr. Maduro’s most powerful ally, Diosdado Cabello, mocked the size of the crowd that had come to receive him at the airport and belittled his movement.
Mr. Guaidó issued a direct challenge to Mr. Maduro a year ago, when he pointed to irregularities in Mr. Maduro’s re-election and claimed to be the country’s interim president, earning the support of millions of Venezuelans and dozens of foreign governments, including the United States.
Since then, despite the United State’s use of crippling sanctions to hurt the country’s economy and try to force the ouster of Mr. Maduro, Mr. Guaidó has not managed to seize power and call new presidential elections — his stated goals.
On Jan. 19, he left the country to shore up greater support abroad, defying a travel ban imposed by Mr. Maduro’s government. On his trip, he made headlines when he sat down with President Trump and was given a prominent place at the state of the union address. There, Mr. Trump championed the opposition leader’s efforts.
Mr. Guaidó also met with Angela Merkel of Germany and Emmanuel Macron of France, and was welcomed by thousands of Venezuelans and Venezuelan-Americans in Florida.
Mr. Trump’s national security adviser, Robert C. O’Brien, signaled that substantive action could be on the way, including sanctions on Russia’s state-owned oil company, Rosneft.
Oil buoys the Venezuela economy, and Rosneft has been the country’s main shipper of crude.
Internationally, Mr. Guaidó looked strong.
But at home, nothing had changed, and Mr. Maduro remained firmly in control of the country, playing what appears to be a long game of attrition.
Mr. Guaidó is also barreling toward a crisis point that poses a critical threat to the opposition, and to his claim to being the country’s interim president.
The National Assembly, the legislature, is the last major political body in the country that the opposition claims to control. But 2020 is an election year for the assembly, and Mr. Maduro’s opponents are divided over whether to participate.
If the opposition does take part, they risk legitimizing a potentially rigged election. If they don’t, they risk handing control to Mr. Maduro.
Mr. Guaidó, so far, has not declared a position.
Phil Gunson, a Caracas-based analyst for the International Crisis Group, said no matter what the opposition decides, Mr. Maduro is likely to take over the assembly this year.
But if Mr. Guaidó does not make a decision — and soon — he risks irrelevancy.
“There can be no more beating around the bush,” Mr. Gunson said. “He has to be a leader.”