“We recognized the nature of the fight was going to change and that we had to ensure that authorities were down to the right level and that we empowered the on-scene commander,” General Votel said. He was speaking specifically about discussions that he said began in November about how the fights in Syria and Iraq against the Islamic State were reaching critical phases in Mosul and Raqqa.

Concerns about the recent accusations of civilian casualties are bringing some of these details to light. But some of the shifts have also involved small increases in the deployment and use of American forces or, in Yemen, resuming aid to allies that had previously been suspended.

And they coincide with the settling in of a president who has vowed to intensify the fight against extremists abroad, and whose budgetary and rhetorical priorities have indicated a military-first approach even as he has proposed cuts in diplomatic spending.

To some critics, that suggests that much more change is to come, in difficult situations in a roiled Middle East that have never had clear solutions.

Robert Malley, a former senior official in the Obama administration and now vice president for policy at the International Crisis Group, said the uptick in military involvement since Mr. Trump took office did not appear to have been accompanied by increased planning for the day after potential military victories.