Pressure from outside Venezuela has also been slow to coalesce. Critics accuse the members of the Organization of American States of failing to constrain the Maduro government, which showers oil bounty on several member nations. A smaller coalition of Latin American countries has joined with Canada to create the Lima Group, whose vociferous condemnation of the political repression has not converted to much concrete action. American sanctions have been steadily tightening in recent years. After a protracted debate between the National Security Council and the State Department, the Obama administration imposed limited sanctions in 2015, primarily targeting the financial assets of individual Venezuelan leaders. Mark Feierstein, who assumed responsibility for N.S.C. policy in the Western Hemisphere later that year, told me the administration had missed a critical opportunity to influence a 2016 negotiation between the Maduro government and the opposition. “The N.S.C., or at least I, was inclined to move more quickly,” he said, “and I think the negotiations largely failed because pressure was taken off.” The Trump administration has expanded the sanctions program, but how far to deepen sanctions, or expand them, or restrict the import of Venezuelan oil, is a brutal calculation about how much of the burden would be carried by the Venezuelan people, and whether adding to their misery is more likely to inspire an uprising or simply worsen the humanitarian disaster.

In recent months, there has also been rumbling about war. Trump has made oblique suggestions of a “military option” in Caracas, and even relatively moderate voices have begun to fantasize about cavalry. In January, the Harvard scholar Ricardo Hausmann, who served as Venezuela’s minister of planning from 1992 to 1993, published a proposal suggesting that the Legislature invite a multilateral invasion force to help support a new government, making a comparison to the liberation of Europe. I spoke with several opposition leaders who welcome this idea, but this might say more about the country’s desperation than the wisdom of the proposal. It’s difficult to imagine Russia and China, after years of propping up the Venezuelan economy in exchange for oil, allowing a foreign invasion to threaten their investment. An even greater concern is internal: Maduro is polling at about 30 percent approval in a devastated economy, but nothing would rally former chavistas to his side like an occupying army. Venezuela is a heavily armed society and increasingly violent. To invite a military intervention is to welcome civil war.

A few months ago, it was possible to imagine an electoral path to change, but today nearly all the opposition parties have been disqualified from running. On the evening of Feb. 15, Maduro took this a step further, interrupting television and radio broadcasts to announce that the party López founded in 2009 is not a political organization but a “violent fascist group” operating “outside the law.” When I spoke with López the next morning, he said that 87 party leaders were already in prison. Those who remained were preparing to convert the party into a “clandestine organization.” Soon, he said, they could be reduced to secret meetings and tossing pamphlets on street corners from unmarked vans.

But even as conditions spiraled down, I watched López try to incorporate what he learned in prison to daily life. Unable to speak publicly, he developed a network of private channels — reconnecting with leaders of the political parties from which he’d split, making inroads with members of the Maduro government and with foreign ministers and heads of state. During the recent negotiation between opposition leaders and the government, López was in contact with all sides; even after his party withdrew from the dialogue, he continued to consult with leaders who remained at the table. When disputes spilled over among them, he provided a back channel, an invisible hub to which it seemed as if all spokes connected.

López was also flexible in his thinking about transition. Through most of our conversations, he strongly opposed the idea of military action, but when we spoke late the other night, he said he was beginning to think differently. An unwelcome mechanism can bring welcome change.

“In 1958, there was a military coup that began the transition to democracy,” he said. “And in other Latin American countries, there have been coups that called elections. So I don’t want to rule anything out, because the electoral window has been closed. We need to go forward on many different levels. One is street demonstrations; a second is coordination with the international community. But this is how I’m thinking now: We need to increase all forms of pressure. Anything, anything that needs to happen to produce a free and fair election.”

If it was jarring to hear this from López, it was matched by another development. For several months, the secret police had been coming to his front door about four times a day to photograph him with a copy of the day’s newspaper. Lately, López had begun to invite the agents in. He had recently spoken with one for more than two hours, offering him a slice of cake from his daughter’s birthday and talking about the inflation crisis and the recent massacre of a small rebel group. “We’ve developed — I wouldn’t say a good relationship, but a relationship,” he said.

Thinking about these developments together, it seemed to me that López was trying to strike an increasingly difficult balance. He was willing to entertain proposals that he found abhorrent six months ago, but he was also making a greater effort to open the door for dialogue. The struggle he faced was a heightened version of the tension in all history. It was to locate the elusive fulcrum between his rage and faith.