Right and wrong are relative.
A “just”, but losing, cause is a contradiction in terms.
Having might alone is of little use, and all conflicts are decided by the might applied.
In Syria, the US had by far the most might but applied very little of it and are “now in the wrong”.
Russia applied sufficient might to defend Assad and break the back of the ISIS resistance and their intervention is now “in the right”.
In Aleppo, Assad and Russia and their Hezbollah/Iran supported groups applied sufficient might and they are now “in the right”.
In Mosul, the US/Iraq/Kurd/Shia militia coalition have as yet applied insufficient might and the outcome and the “rightness” are still to be decided.