Tom Tugendhat told MPs it “does not have to be defeat” but “damn well feels like it” in an emergency sitting to discuss events in Afghanistan.
The Taliban took over the country at the weekend after a rapid offensive saw it seize control of major cities and move into Kabul on Sunday.
“Like many veterans, this last week which been one which has seen me struggle through anger and grief and rage,” Mr Tugendhat told MPs on Wednesday.
“The feeling of abandonment of not just a country, but of the sacrifice that my friends made.”
The MP, who chairs the foreign affairs select committee, said: “I have been to funerals from Poole to Dunblane. I have watched good men go into the earth, taking with them a part of me and a part of all of us.
“This week has torn open some of those wounds. Left them raw, left us all hurting.”
Mr Tugendhat said it was with "great sadness" that he was to criticise the US, noting: "To see their commander in chief call into the question the courage of men I fought with, to claim that they ran is shameful.
"Those who have not fought for the colours they fly should be careful about criticising those who have."
Tory politicians have criticised Joe Biden’s speech justifying his decision to pull troops out of Afghanistan, in which the US president argued the country’s political leaders “gave up and fled the country” rather than resisting the insurgents.
Mr Biden had said: “The Afghan military collapsed, sometimes without trying to fight. American troops cannot and should not be fighting in a war and dying in a war that Afghan forces are not willing to fight for themselves.”
Mr Tugendhat also told parliament on Wednesday: “We need to turn out attention to those who are in desperate need.”
He also described how a man once walked into a base with a child who had died hours earlier, begging for help.
“There was nothing we could do. It was over. Because Mr Speaker, this is what defeat looks like. It is when you no longer have the choice of how to help,” he said.
“This doesn’t need to be defeat. But at the moment, it damn well feels like it.”
MPs have praised Mr Tugendhat for his speech, with Tory colleague Dehenna Davison saying it was “one I will remember for the rest of my life”.
Labour’s Wes Streeting wrote: “Britain is very fortunate to have soldiers like TomTugendhat and parliament is very lucky to have his wisdom and experience leading the Foreign Affairs Committee. Magnificent and moving speech during the Afghanistan debate.”
And Liberal Democrat MP Jamie Stone posted: “A most extraordinary, moving speech from my brave colleague Tom Tugendhat.”
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