It will be very difficult to see the U.S. winning in Afghanistan but President Donald Trump had no easy options, Peter Westmacott, former U.K. ambassador to the U.S., told CNBC Tuesday.
President Trump changed his mind and .
Though he did not clarify how many soldiers would be deployed, he said the U.S. would not be focused on nation building but more on "killing terrorists."
"The president was obviously reluctant to go down this path," Westmacott told CNBC.
He said that Trump was probably influenced by the departure of Steve Bannon, a key advisor, and by very senior generals in the administration.
"It's going to be for this (decision) to be a win, as the president says, but there were no easy options and not doing something like this, he was advised it would make things a lot worse, and it would increase this insecurity, the risk to America from terrorist organizations running around in the Afghanistan," Westmacott said.
The U.S. military has been in Afghanistan for more than 15 years. Media reports suggest that up to 4,000 new U.S. soldiers could be deployed.
NATO, the defense alliance, welcomed on Tuesday the decision taken by President Trump. The group, who agreed to send troops to Afghanistan after the 9/11 attacks, has currently more than 12,000 troops in the country.
Secretary-General Jens Stoltenberg recalled Tuesday that NATO had already committed to increasing its presence in Afghanistan.
However, President Trump should not expect a substantial support from his NATO allies, Westmacott warned.
"Yes, he will want NATO partners to be there but to be honest, the numbers that people are putting in, even the United Kingdom which has been a steadfast ally in this venture, are modest," he said.