A common explanation is that these tyrants are better at playing the game. They are strategic geniuses leading governments with decades of experience in foreign affairs and characterised by single-mindedness and a long-term horizon. Of course they are going to make better geopolitical moves than democratic governments riven by political factionalism and only able to think as far ahead as the next election.
This explanation is wrong. Tyrants don’t succeed because they are especially skilled at the game of geopolitics, but because they are baddies. Tyrants make bold moves because they are willing to subject their country (and the whole world) to more risk. They can do that because they care less than democrats, and hence worry less, about bringing harms to their people. Like a hedge fund manager, they can afford to take big risks because they are not playing with their own money. When tyrants win it is because of luck, not brilliance. This is easier to see when tyrants lose – as they nearly all do in the end, when their luck runs out.