Allowing the city of Basra to descend into a chaos and violence filled hellhole is to evidence of an arse kicking, in a political and strategic sense.
Not only in a military sense.
Now, when you invade a country and then that country descends into chaos on your watch, in this case the part of the country called Basra, conditions not coming anywhere close to any level of calm and stability, then I do say the occupying force received a solid thumping.
So you’ve been to basra lately then???
Then you would presumably call Vietnam the mother of all defeats for the US?