It was not clear whether the C.I.A. would be enthusiastic about resuming a role in detaining and interrogating terrorism suspects after its scorching experience over the past decade. In written answers to questions by the Senate Intelligence Committee, Mr. Trump’s C.I.A. director, Mike Pompeo, said he would review whether a rewrite of the field manual was needed and left the door open to seeking a change in the law “if experts believed current law was an impediment to gathering vital intelligence to protect the country.”

Mr. Trump’s order says no detainee should be tortured or otherwise subjected to cruel, inhuman or degrading treatment “as prescribed by U.S. law,” but it makes no mention of international law commitments binding the United States to adhere to humane standards even if Congress were to relax domestic legal limits on interrogations, such as the Convention Against Torture or the Geneva Conventions.

Another core national security legal principle for Mr. Obama was to use civilian courts, not military commissions, whenever possible in terrorism cases — and to exclusively use civilian law enforcement agencies and procedures, not the military, to handle cases arising on domestic soil. The draft order also signals that the Trump administration may shift that approach as well.

In 2012, after Congress enacted a statute mandating that the military initially take custody of all foreign Qaeda suspects, Mr. Obama issued a directive that pre-emptively waived that rule for most domestic circumstances, such as if the F.B.I. had arrested the suspect and was already in the process of an interrogation.

But Mr. Trump’s draft order calls for the attorney general, in consultation with other national-security officials, to review that directive and recommend modifications to it within 120 days.

Many Republicans — including Senator Jeff Sessions, Mr. Trump’s attorney general nominee — criticized the Obama administration’s approach as weak, even though the civilian court system has regularly convicted terrorists at trial while the military commissions system has proved to be dysfunctional. During the campaign, Mr. Trump said he would prefer to prosecute terrorism suspects at Guantánamo — including American citizens, although the law currently limits the commissions system to foreign defendants.