If you can’t blame the failures of your policy on some flunky (or opposition party, if you’re unlucky enough to be ruling in a “democracy”) then what kind of leader are you?
The best option is to say that your policy is a rousing success, in spite of all evidence. (That is, if you can’t suppress the evidence.)
Of course, as a intergalactic overlord, I’ve always felt that the best foreign policy comes from the “offer them a Stay-Fresh Snakin’ Cake … and carry a plasma weapon” school. Here on Earth you face the challenge of multiple opponents/allies who are impossible to defeat militarily, without destroying your biosphere, that is. (What is it with your human fascination with those quaint nuclear weapons? Don’t you realize they can wipe out everything?)
So no. Don’t ever take ownership of a mistake! I mean, if you admit to a mistake, then you might actually learn something, and do better the next time.
How the hell am I going to conquer you people if you start learning things?
Next time: Henri Bergson described time as something we experience as a duration, in a flow of consciousness, not as a series of events. So what gives with knock, knock jokes?