Mr. Velasco, the historian, said it was not surprising that Venezuela’s top military officials haven’t backed the opposition.
In recent years, Mr. Maduro has faced small uprisings by the nation’s security forces. Knowing how critical they are to his grip on power, he has offered the military incentives, including control of large parts of the legal economy, along with lucrative drug smuggling routes and other illicit trades, Mr. Velasco said.
“They are ultimately the ones who not only have the firearms, they are so deeply implicated in the corruption of the state that having them onboard is an absolute necessary condition to pushing out Maduro,” Mr. Velasco said.
The opposition has been targeting the middle ranks, holding meetings with midlevel officers to explain a recent amnesty law passed by the opposition-led National Assembly for people who defect, according to a prominent opposition member.
Carlos Peñaloza, a former chief of staff of the Venezuelan Army now in Miami, said he has been in touch with disgruntled midlevel officers in recent weeks and believes that their numbers are enough to overthrow Mr. Maduro, with or without support of Venezuela’s top commanders.
“Many majors, lieutenants and colonels — they began their careers before Chávez,” he said, adding that they did not owe allegiance to Mr. Maduro. “They were raised in democracy and want to see it restored.”
Mr. Peñaloza said an embargo on Venezuelan oil by the United States might lead to mass defections in the military. The 500,000 barrels a day of petroleum that Venezuela sends to the United States are believed to be the principal source of hard currency for the government, and one of the main incentives top military brass have had to remain loyal.
“Maduro wouldn’t have the money to pay them,” he said.