Waifu Wars (also known as "The Great Waifu Wars of Fire Emblem Awakening") were (and actually still are) a series of ongoing battles pitting the armies of various different waifus against each other in the quest to determine who is the best waifu. While the greatest battles are a thing of the past, there are occasional skirmishes and battles that flare up once in a while.
The conflict started as soon as (or even before, since much content was leaked) the game was released in the Western World. Each person saw the various waifus available in the game and was free to choose to whom he wanted to pledge his loyalty to. After he joined, he was honor bound to defend his waifu as the waifu of choice against the armies of others who claim theirs is the one true waifu. With so many choices, vast armies quickly mobilized under the banner of their chosen waifu. It was only a matter of time before these armies met each other on the field of honor to defend their waifu.
Carnage and Canon
It is unclear which camp fired the first shot, but once that happened, all hell broke loose. All of the soldiers engaged in battle with the army (or armies, when the battle encompassed more than one waifu) of the enemy camp. There was a lot of arguing, namecalling, insulting, intransience, straw pulling, trashing others' waifus while insisting that theirs was the one, and many other unpleasantries. This was the bloodiest period in the conflict.
What fueled the drive of many soldiers was the belief that they had the (highly subjective) secret weapon known only as "canon" on their side. It was this belief, the belief that their waifu was the one that the Avatar was meant to end up with, that their waifu was the "official" spouse of the Avatar, that sustained the soldiers through sieges, enemy attacks and cold winter weather and inspired them to continue the fight. Each army was so convinced that his waifu was "canon" that they drew on anything to support their position, from the (somewhat) reasonable to the downright ridiculous.
During the first year after the game's release, there was much arguing and many casualties on all sides (chief among them being the "rationalists", who tried to peacefully and reasonably say that canon is subjective and everyone should live and let live). But the conflict raged on.
After the greatest battles died down, the war evolved from a "hot" conflict to a "cold" conflict. Each side acknowledged that others had opinions and were not about to change them anytime soon. The argument of the rationalists spread amongst all sides and even the most hawkish generals toned down their rhetoric. So, a period of begrudging coexistence emerged. While this era of peace persists to this day, each side is still heavily armed and thus, the occasional conflict does flare up. However, these conflicts do not reach the levels found early in the war.
Notable waifus and their armies
While each waifu does have her fair share of supporters, there were inevitably ones whose armies are bigger than those of other waifus.
By far the biggest and most dedicated army. Well funded and well equipped. Her army came closest to finding the elusive "canon" because of Operation: Chapter 21 changes if you marry her. Her army's dedication was rewarded when their researchers delevoped the "special dialogue: Bathrealm" rifles and the "Bathrealm : Yukata" armor. Another major breakthrough was when Lucina was included in the new Super Smash Brothers game alongside Robin. These developments renewed the confidence and dedication of her soldiers. She continues to attract new recruits every day. Her popularity endures even after all these years and she manages to win various popularity polls.
Possibly the army who comes closest to matching that of Lucina. Well organized and dedicated. Their researchers developed "special dialogue: Summer Scramble" and "Summer Scramble: Swimsuit" armor. With the efforts of her army, Cordelia consistently comes in the top three popularity polls.
Smaller than the aforementioned armies, but equally dedicated. Somewhat less belligerent too. This group specializes in stealth and infiltration. They are aided by their waifu having large assets, being a dragon and having appeared in previous games.
- The Waifu Wars can be seen as running parallel to the Canon Conflict (or within it, or the visa versa, depending on one's viewpoint)
- The so called "Husbando Wars" are the (smaller scale) Rule 63 version of the Waifu Wars
- Waifu Wars are commonly believed to be a subdivision of Waifu Emblem.