Can you elaborate on "couldn't hold it" in the context of the Iraq war? It makes sense with Afghanistan due to the Taliban filling the void, but doesn't Iraq have roughly the same government and stability that it had when the US left / withdrew?
"In January 2020, during massive protests[3] and following an escalation of tensions between the United States and Iran, the Iraqi Council of Representatives passed a non-binding measure to "expel all foreign troops from their country," including American and Iranian troops. "
Iraq study estimates war-related deaths at 461,000
https://www.bbc.com/news/world-middle-east-24547256