ABOARD A B-52, over Eastern Afghanistan — Flying at more than 20,000 feet, the hulking long-range bomber circled ominously above a militant-infested swath of Afghan territory near the rugged border with Pakistan, hunting for Taliban or Islamic State fighters who could threaten friendly troops nearby.

A ride in the cockpit on a recent 13-hour combat mission provided a rare bird’s-eye view of the Trump administration’s newly revamped Afghanistan policy of sending thousands of additional American troops closer to the front lines — and more warplanes like this one to protect them. That includes striking Taliban drug depots to cripple the group’s financial lifeline, as the Pentagon did in Iraq and Syria in hitting the Islamic State’s oil tankers and cash-storage sites.

During the Obama administration, American commanders were barred from carrying out offensive airstrikes against the Taliban. Attacks had to be defensive, aimed at protecting Afghan forces on the ground, conditions that commanders complained tied their hands and led to a stalemate. Now the gloves are off, and American warplanes have already dropped more than 3,900 bombs and missiles against targets in Afghanistan this year, three times as many as last year.

“These new authorities give me the ability to go after the enemy in ways that I couldn’t before,” Gen. John W. Nicholson Jr., the top American commander in Afghanistan, said last month after ordering the new operation, code-named Jagged Knife. “We’re hitting the Taliban where it hurts, which is their finances.”