WASHINGTON — Nobody said regime change was going to be easy.

President Trump’s top advisers woke up Tuesday believing that a rebellion in the Venezuelan military that day would galvanize a popular uprising and topple a leader they have described as a reviled despot who must be replaced. But at day’s end, President Nicolás Maduro was still in power and Mr. Trump’s advisers were left to blame Cuba, Russia and three influential Venezuelan officials, who failed to switch sides, for frustrating their plans.

The decision of the Venezuelans to stand with Mr. Maduro — either because they were intimidated, got cold feet or never planned to defect — raised questions about whether the United States had faulty intelligence about the ability of the opposition to peel away members of his government.

It also raised questions about whether Mr. Trump’s aides had fallen victim to a misreading of events on the ground, or whether Mr. Trump, who officials say has sometimes outrun his aides in an enthusiasm for forcing out Mr. Maduro, might lose faith in the effort as it wears on.

Mr. Maduro has been weakened at home and discredited abroad, but he remains a stubborn rival unwilling to step aside for the opposition leader, Juan Guaidó, recognized by the United States as the country’s de facto leader. While the administration got off to a sure-footed start on Venezuela, rallying dozens of countries against the Venezuelan president, critics said its response had become haphazard and chaotic as the crisis has dragged on.