AP Photo/Carolyn Kaster
In an address in Virginia, Trump said he sympathized with Americans who were "weary of war without victory" and said that he shares "the American people's frustration" with a "foreign policy that has spent too much time, energy, money, and most importantly lives trying to rebuild countries in our own image."
"My original instinct was to pull out, and historically I like following my instincts, but all of my life I heard that decisions are much different when you sit behind the desk in the Oval Office," Trump said.
"So I studied Afghanistan in great detail and from every conceivable angle. After many meetings, over many months, we held our final meeting last Friday at Camp David, with my cabinet and generals, to complete our strategy," he said.
Lamenting that he was dealt a "bad and very complex hand," the president said several factors led him to implement "a shift from a time-based approach to one based on conditions."
Trump cited the troop drawdown in Iraq, which he argued allowed ISIS to gain ground in the country, as well as a perceived threat from terrorists in Pakistan. He also called on other US allies to pitch in, singling out India as a trade partner.
Trump also insisted that Afghanistan strategy would be conducted in a manner that was coherent with his campaign vision, saying he would not give timetables for withdraw or troop levels.
"We are not nation building again," Trump said. "We are killing terrorists."