What US is facing is the limits of air war. No regime has been changed in the history of the world via aerial bombardment.
This will be considered a loss. It isn't just the regime, it is the "gusto" they went in with, over in weeks BS and the like. If they send ground troops, it will drag out for many years. Poor Trump legacy...
In order to change the regime it would require a ground operation like in Iraq.
Did the US win in Iraq you think?