Great War (Total Eclipse of the Heart)
From Tardis Wiki, the free Doctor Who reference
According to Danielle, a Great War was fought on Earth during the 2060s. The Great War ended with an agreement of ceasefire, after the realisation that the conflict was slowly destroying the planet itself. The Unified Earth era, a time of peace and prosperity, followed the war.
In 2070, all nations on Earth collaborated in building the colony ship Heart. This shared vision for humanity's future was a key factor in maintaining global peace, and Danielle went as far as to call Heart "the reason the war is over". (PROSE: Total Eclipse of the Heart)