MPs were part of a "vacuum of Western leadership" responsible for the tragedy of Aleppo, former chancellor George Osborne has said.
The backbench Conservative MP told the debate in the Commons there were "multiple opportunities to intervene" in the bloody Syrian conflict since it began in 2011.
"It is something we could have foreseen and done something about," Mr Osborne said.
Referring to Parliament's majority vote against military action against Syria in 2013, he said: "We are beginning to learn the price of not intervening in Syria."
He added: "Let's be clear now: If you don't shape the world, you will be shaped by it."
ITV News Political Editor Robert Peston said it was a "savage" attack on the failure of the West.
Tens of thousands of civilians desperate to leave Aleppo were left stranded for 48 hours over the weekend after a ceasefire deal broke down.
Dubbed the People's Convoy, aid workers intend to take medical supplies to a new children's hospital in Syria.
Watch all of ITV News correspondent Dan Rivers' reports on the end of the battle for Eastern Aleppo and the evacuation from the city.