Why?
Some things that you break cannot be fixed because they are generationally broken and it takes a minimum of 30 years of management to get the first new generation in places of power or importance in a new regime like democracy in a place that has never had anything but tyranny or kings.
So if you leave early, and new tyranny replaces the old and what did you accomplish.
I made one exception, when I said that Cold war proxy battles in some little state are not intervened in for the same reasons. They have a bigger purpose and that is to destabilize your foe. The Proxy is just caught in the middle. You let your foe fix it.