14Six Week Peace
The Coalition of Ordered Governments (COG) and Union of Independent Republics (UIR) waged a decades long war between each other, resulting in millions dead and only ending when the Locust eventually emerged from their Hollow, unleashing havoc upon the planet surface.
While it may have been fitting for the Locust, in
all of their tactical savagery, to time Emergence Day to ensure that they caught humanity at its weakest, it turns out that E-Day didn't actually occur during the Pendulum Wars, and wasn't the cause of the COG/UIR battles to stop. As it turns out, E-Day actually occurred about six weeks after the COG and UIR signed a peace treaty, bringing an end to the Pendulum Wars. All in all, humanity only had these six weeks to recover and prepare for a war that they never expected.