And later in 2017, Mr. Trump rescinded a set of rules, known as the Presidential Policy Guidance, that the Obama administration had imposed on counterterrorism operations away from hot battlefields. Those limits included a requirement that targets of kill missions by the military and the C.I.A. be limited to high-level militants rather than foot-soldier jihadists without any special training or leadership role, and a requirement for high-level, interagency vetting of proposed attacks.

Still, Mr. Trump’s changes in 2017 left in place a requirement that strikes away from conventional war zones take place only when military officers had “near certainty” that no civilians would be killed. Similarly, his executive order on Wednesday left in place other aspects of Mr. Obama’s directive that require the government to make a priority of preventing civilian casualties.

“The United States government is fully committed to complying with its obligations under the law of armed conflict, minimizing, to the greatest extent possible, civilian casualties, and acknowledging responsibility when they unfortunately occur during military operations,” the National Security Council statement said.

In a sense, Mr. Trump’s revocation of the disclosure rule amounted to a belated acknowledgment that his administration had already changed the Obama policy in practice: The director of national intelligence never put out a report about bystander casualties in 2017, even though the Obama-era order requiring one remained on the books last year, when the report was due out.

Several other factors somewhat lowered the stakes of Mr. Trump’s move. First, the C.I.A. appears to be carrying out fewer drone strikes than it did during the height of the Obama administration’s counterterrorism operations.

The last drone strike was reported more than a year ago in the tribal area of Pakistan, where the C.I.A. took the lead in handling airstrikes, according to Bill Roggio, a senior fellow at the Foundation for the Defense of Democracies, who has tracked airstrikes for more than a decade on his Long War Journal. While Yemen is still being bombed, it is hard to determine whether the American government or the Saudi-Emirati coalition battling the Houthis, an Iran-allied rebel faction, are conducting the strikes, he said.

Moreover, even when the Obama administration revealed the official assessment of how many civilians had died, those numbers were merely a vague range and lower than estimates by outsiders like the Long War Journal, the Washington-based security policy organization New America and the London-based Bureau of Investigative Journalism.