The UK and its allies "reserve the right" to launch new military action in Afghanistan should international terrorism thrive, the Government has said.
Defence minister James Heappey has left the door open for military action should "ungoverned spaces" return which pose a threat to the UK homeland or the interests of allies, as well as the option of providing air support to Afghan forces.
The Afghanistan veteran also suggested a review will be carried out into Britain's military involvement in the country.
Mr Heappey, who completed two tours the country, spoke of his first reaction to news that international troops will withdraw later this year: "Like every other Afghanistan veteran when I heard of NATO's decision last week, I couldn't help but ask myself 'was it all worth it?'"
He did, however, insist that he hopes there is a successful political outcome in Afghanistan, telling MPs it is "almost certain" that a lasting peace settlement will "involve the Taliban as part of the Afghan government".
Defence Select Committee chairman Tobias Ellwood warned that Afghanistan is "heading towards another civil war" with the Taliban on the rise.
He said: "This cannot be the exit strategy we ever envisaged.
"Our nation and our military deserve answers.
"So, I request a Chilcot-style inquiry so we can learn the lessons of what went wrong."
WATCH: The Foreign Secretary was pressed on whether UK troop reductions and the withdrawal from Afghanistan sent the wrong message to Russia.
Mr Heappey responded: "It's not for me to agree to such an inquiry right now but one would hope the lessons would be learned."
Noting the changes in the country since 2001, Mr Heappey mentioned the reopening of schools and girls having education, before adding that the Afghan security forces are a "proud army with the capacity to keep the peace" if needed and the country's people have "tasted freedom and democracy".
Former minister Mr Ellwood had earlier told the Commons: "If we depart completely, a dangerous part of the world becomes more dangerous as the Taliban assumes control of the bulk of the country and, once again, gives sanctuary to extremist groups.
"Our brave military served with honour but they were let down by poor strategic judgments, that if politicians today do not understand and learn from will impede our confidence to step forward and stand up to extremism and authoritarianism in the future."
Mr Heappey replied: "We have reached a point where the military mission has effectively culminated and what remains is a requirement for politics."
Shadow Defence Secretary John Healey said Afghanistan has been "more failure than success" for the UK's Armed Forces.
Addressing the Commons, he said: "There certainly have been some gains – governance, economic development, rights for women, education for girls, and ending Afghanistan as a base for terrorism abroad – but Afghanistan is more failure than success for the British military.
Watch: A look back on 20 years of British forces in Afghanistan.
"And now with the full withdrawal of NATO troops, it's hard to see a future without bloodier conflict, wider Taliban control and greater jeopardy for those Afghanis who worked with the West, and for the women now in political, judicial, academic and business roles."
James Heappey responded: "I'm not sure that I accept [Mr Healey's] characterisation of it being defeat. I think that many of them, as I do, will reflect on the tactical and operational successes that they had within their individual tours, within the districts that they were responsible for.
"If you arrive in a district and the school is shut and when you leave the school is open, or you arrive in the district and the market has got six stalls and when you leave it's got 20, those are the sorts of successes that show you with your own eyes that your service there has been worth it and that you have done good."
Mr Heappey also stressed that any disagreements over troop withdrawal focused around a "matter of months" rather than years.
MPs heard 150,610 UK personnel have served in Afghanistan in the past 20 years, with hundreds suffering "life-changing injuries" and 457 deaths recorded.
The discussion comes after the head of Britain's Armed Forces expressed disappointment at President Joe Biden's decision to withdraw US troops from Afghanistan.
Mr Biden announced that the 2,500 US troops who remain in the country would leave by 11 September – the 20th anniversary of the 9/11 attacks on the US – extending the 1 May deadline set by his predecessor, Donald Trump.