Source: Season 5, Episode 26.
I was just thinking about the season five finale. Each alternate timeline showed us what would happen if a different villain hadn't been defeated. In each one, there was some sort of major resistance. During the fight against Sombra, Equestria essentially turned into WWII Britain, complete with giant battles, railroads to safety, and a society that has pointed every ounce of its industrial weight toward the war effort. During the fight against the changelings, ponies took to the hills, and became merciless guerilla warriors - even Fluttershy.
Nightmare Moon, however, while clearly a tyrant, continued to command the loyalty of her subjects. It's not a pleasant timeline. Based on the fear, and exhaustion we see in those around her, one gets the impression that a single day of serving Nightmare Moon is like an entire chapter of The Devil Wears Prada. Still, this segment stands out because there was no resistance movement (that we saw), and because main characters serve the villain.
Personally, I find it difficult to extract easy answers from the situation, since I think that I, personally, would fare very well in a Lunarchy. If my job were to follow Nightmare Moon around and tell her how beautiful the night sky is, I would consider it a dream come true. Especially if this were a world where I didn't know that there was such a thing as good Princess Luna.
However, my own admittedly ridiculous feelings aside, the episode itself raises questions about monarchism in Equestria. Is princess worship a more deeply-ingrained value than friendship, (at least in a world before the Elements are rediscovered)? Do ponies accept tyranny more readily from leaders that they perceive to be "of their tribe," than they would from foreign invaders with similar ambitions? I think a lot of us do that very thing, so long as the societal infrastructure that we are accustomed to remains familiar.
I think the most important thing that we can take away from this segment is a lesson on the nature of ambition. The two main characters that we see serving Nightmare Moon most directly are Rainbow Dash, and Rarity - easily the most ambitious ponies in the Mane Six. Decorating for a princess – even an evil one – is a prestigious career move for Rarity; and Rainbow Dash has always endeavored to rise through the ranks - to become a prominent Wonderbolt - to prove herself.
In seeing Rainbow Dash serve Nightmare Moon with such ferocity, and Rarity serve her so tirelessly, there is an entire backstory – a whole elaborate lesson, right there in just a few short minutes. What we are seeing is their virtues – parts of their very souls – being twisted, and used against them. Raritiy's generosity, and willingness to give of herself creatively - it ends up getting abused, until she is absolutely exhausted. Rainbow is even worse. Her loyalty, when misdirected, turns her into a savage attack dog.
There's so much to think about in what we saw of Nightmare Moon's Equestria - who we are as individuals, what we have the capacity to become if we aren't careful, how troubled times can sculpt us. I think the problem with a situation like this, is that nopony can prepare for it. In real life, everyone has very specific ideas about what they would have done had they lived through INSERT HISTORICAL PERIOD HERE. The fact of the matter is that none of us really know.
The paths before us are not straight lines. The best that any of us can do is to follow our own hearts, and be sharply aware of the fact that they can be used against us. Our ambitions can lead us to dark places. Our virtues can betray us, if they are not guided by principle.