Trump's changing views on Afghanistan

US President Donald Trump on Monday cleared the way for the deployment of thousands more US troops to Afghanistan, committing to an open-ended conflict in the country after 16 years of war.

At the height of US involvement in 2010-2011 America had roughly 100,000 troops in Afghanistan, before President Barack Obama reduced that number to 8,600.

In outlining his administration's "path forward" for Afghanistan Trump gave no indication of how he would use other instruments of US power to end the conflict, saying America was intent on "killing terrorists" rather than "nation building".

His new strategy marks a sharp departure from his old views on the conflict.

Since 2011, Trump has mentioned Afghanistan in 48 tweets, according to the Trump Twitter Archive website, nearly all of which lambasted US involvement in the country.

In 2011 during Obama's troop surge he wrote on Twitter: "When will we stop wasting our money on rebuilding Afghanistan? We must rebuild our country first."

A year later he said on social media that "it is time to get out of Afghanistan", saying "we are building roads and schools for people that hate us."

In January 2013, he said America should "bring our troops home, rebuild the U.S., make America great again".

Several months later he wrote that "we should leave Afghanistan immediately".

After Obama decided to keep troops in Afghanistan in 2014, he again criticised the former president, saying "he is losing two wars simultaneously."

His views on Afghanistan began to change but still remained contradictory and confused.

In a 2015 interview with CNN he said the US had made a "terrible mistake" getting involved in Afghanistan, calling it a "mess".

In the same interview he later said "at this point, you probably have to (stay in Afghanistan) because that thing will collapse about two seconds after they leave".

In the 2016 Republican presidential candidates debate he said "you have to stay in Afghanistan for a while", pointing to the presence of nuclear-armed Pakistan next door.

Largely quiet about Afghanistan during the first seven months of his presidency, last month he discussed the conflict with service members.

"I've heard plenty of ideas from a lot of people, but I want to hear it from the people on the ground."