WASHINGTON — Intelligence briefers regularly present President Trump with a classified map of Afghanistan, usually the only report on the war he examines, displaying the strikes carried out in recent days and, critically, the number of Taliban and other militants killed.

During his presidency, enemy body counts have been the lens through which Mr. Trump has viewed the Afghanistan war — an often meaningless metric in disrepute since the Vietnam War.

Now, America’s de facto war of attrition against the Taliban has, at least theoretically, come to an end. The signing of a deal on Saturday in Doha, Qatar, to start withdrawing United States troops from Afghanistan may not immediately stop the fighting, but it will at least usher in a new era in the 18-year war.

The deal will also begin the process of drawing down the American intelligence presence.

There are many questions about what the role of the remaining military forces and intelligence officers will be, but the rough outline of how the mission is likely to shift has become apparent.