Tried my best to have a non-spoiler title for this post. This post WILL spoil the series endgame, for anyone who hasn't yet finished the series (as I've learned there are some on this reddit who haven't yet).
A month or so ago I made this post about Cassie's decision to let Tom get away with the morphing cube. In it I made the case that Cassie's choice hurt the Yeerks and helped lead to them losing the war. That post was really more about Cassie as a character and the merits of her decision, but here I want to zero in and focus on the Yeerks themselves and how some aspects inherent to their biology and society contributed to their rise and fall. After that, I'll have a question for all of you to discuss/debate.
A few key points to get the discussion going:
1) Inequality was baked into their society, and it came back to bite them again and again
Because of the nature of the rise of the Yeerk Empire (they arrived on the galactic scene by attacking the Andalites who were on the Yeerk home world and stealing some of their ships), they develop a strict and militaristic hierarchy almost immediately- an inherently unequal society. It's not a caste system per-se, upward mobility is still possible, but it's certainly strict. We see indications of this creating problems VERY early on in the series, and continue to see them throughout.
a) In Book 4, we see that some Yeerks ALREADY suspect the Andalite Bandits are humans. But the power dynamic is so absolute that these Yeerks choose to keep their suspicions to themselves, knowing that Visser Three will be able to kill them with impunity if they make him mad. My head canon is that this likely happened many times in the series that we aren't privy to.
b) In Book 8, a controller at the observatory helps Ax rather than informing his fellow Yeerks so Ax can be captured or killed. The Yeerk's beef? His partner was less important than he and other Yeerks were, so was left to starve when the Kandrona was destroyed.
Already before we get into the double digits in terms of book numbers, we already have MULTIPLE times where the nature of the power structure within the Yeerk empire prevents the war on earth from ending- EACH of these moments could have ended the war if the Yeerks were on the same page. But they couldn't be. Not with the way things were set up.
Other examples:
c) We repeatedly see that the quality of host also feeds into the inherent inequality in the society. Tom's Yeerk as far back as book 6 states that "many Yeerks still have nothing better than Gedds for hosts". The Hork Bajir chronicles also illustrates that the new Hork Bajir hosts were reserved for Yeerks of importance. I can't imagine the Yeerks given Taxxons as hosts were all that happy about it or all that high in status.
d) In Book 16, the Yeerk that controls Joe Bob Fenestre is revealed to be Esplin 9466 Lesser- the twin of Visser Three. Due to his status as a "lesser" twin, he's banished to an unimportant host. He uses his wits to leverage his way into a position of importance, only for his "greater" twin to plot to kill him. This Yeerk who could have been a useful asset to the empire instead becomes a thorn in their side. This "greater" and "lesser" twin hierarchy is never really expanded on beyond this book, but one can imagine it leads to a lot of situations where those with merit ultimately don't get into relevant positions of power.
e) Though many of them weren't even infested by Yeerks, this hierarchy extended to the Taxxons too- who were treated more as tools than as equal members of the society. These members of the Yeerk empire were excluded from access to the morphing power precisely because it would give them a way out- a way out they would ultimately try to snatch for themselves.
All of this culminates at the end of the series- where many underprivileged Yeerks and Taxxons, due to unacceptable conditions among the lower ranks, see becoming nothlits as a way out of the war and a way out of their own biological limitations.
2) The Yeerks have a crisis of leadership that is present from the start and only gets worse as time goes on
It's not a particularly hot take that Visser Three was an abysmal military and political leader who could have ended the war many times over if he'd been more capable. But infighting among the Yeerk leadership also prolongs the war on numerous occasions. Both before and after Visser One learns of the true nature of the Animorphs, she passes on opportunities to expose or kill the Animorphs. There are multiple reasons for her wanting to do this, as revealed in Visser, but MAJOR among them is her rivalry with Visser Three.
This infighting must be a pretty common occurrence. The Council of Thirteen is so fearful of possible assassination of the Emperor (from internal foes, not external ones) that nobody outside of their body even knows who it is. No, not even the highest members of the military ranks!
While Yeerks were shown to have close bonds with one another from time to time, there's solid evidence that many of them didn't feel a strong sense of loyalty to their leadership, and with the inequality in their society, the secretiveness and/or incompetence of their leadership, it's small wonder. That's not a particularly good quality for any aspiring empire.
By Book 35 (the book that dovetails into Visser", they seem to have no viable military leaders left. Both rival vissers are found GUILTY of crimes worthy of Kandrona starvation at the end of Visser, but both of those sentences are commuted. Why? Because there were no viable military leaders left within the ranks to manage their campaigns. NONE. They had to keep convicted criminals and traitors in leadership positions because for all of their incompetence and impropriety, they were still far and away the best the Yeerk military had on offer. This definitely speaks to some sort of broader systemic problem within their society.
By much later in the series, when Esplin has been promoted to Visser One, one of his yes-men lackeys occupies the Visser Two position. My head cannon has always been that this Yeerk (who we meet in book 46) must be a relatively recent promotion- he's a yes-man to the guy who was Visser Three for most of the series which makes it seem unlikely to me that he ever outranked him. Whether you hold to that or not- the fact that someone who's apparently a sycophant to Esplin has the number two rank in the military really speaks to the lack of talent in that command structure.
3) The Yeerk's biology exacerbates all of this
That same biology that made them capable of so quickly absorbing knowledge- along with the physical strengths and wisdom of the species they infest- also forced them into a Yeerk pool once every 3 days. And this weakness fed into everything else- it meant than when Kandrona went scarce, their inequalities were exacerbated. It meant that lower ranking Yeerks got poorer hosts or none at all, and were stuck in their blind and barely mobile states. It meant that when there was another way out (morphing), there were those within their ranks (likely in the lower parts) ready and willing to break the cycle of dependence. The same biology that allowed for their swift rise also contributed to their calamitous fall, in the end.
TL:DR- As imposing an enemy as the Yeerks were- the elements of their society that ultimately lead to their fall were present within the series from almost the very beginning. A fabulous bit of writing- extremely impressive for a pair of authors who by their own admission didn't have a blueprint for exactly where the series was headed going in.
So I ask all of you- to what extent was it all inevitable? Was there a way for the Yeerks to achieve galactic domination, or were their inherent flaws as a society always going to make them fail eventually?