Rise of Space Power
Some historians argue that the beginning of the end of the Grand Army Era was the birth of interdimensional spaceflight, and the establishment of Web Dimensional Theory. For a time prior to the launch of SAGA, fielding a space fleet became an expression of limited independence from the Grand Army's authority. It was the first time nations had tasted such independence since before the Great War.
Nations like Guardia and the Kingdom of Carrion had already conducted unmanned spaceflight, and both nations fielded impressive flotillas of airships and planes. But late in the year 28 WR a race began between the two powers that would decide the fate of Web space for the coming decade. The goal was to develop a viable fleet of manned space craft.
It was the Guardians who discerned the true prize of the race, however. Using high-powered telescopes and unmanned satellite transmitters in Crystal and Gate, Belthasar the Guru of Reason established as fact that the Dimensions were not alternate universes (as had previously been believed), but were rather parts of a contiguous universe. Given that as true, the Guardians believed that space flight between the dimensions was possible, and that the first nation to attain that ability would be a dominant power in the Web for a long time to come.
While the Carrionese focused their efforts on building luxury travel craft on a grand scale, an endeavor which slowed them down considerably, the Guardians set to work on building much smaller craft at the summit of Death Peak. While separate endeavors were being undertaken by Malvo Thames to refit the Guardian Airforce into a fleet of aerospace-capable military vessels, Belthasar directed the construction of three small capsules that would make the first interdimensional spaceflight.
The importance of the symbollic victory was no small thing: the flight across the Gate-Crystal Strand drew the Web's eye on Guardia and took the wind out of the Carrionese sails. By the time the Carrionese began to pick up the pace on their work again, the GSF was online and had established small patrols in most of the Web's dimensions. Formal colonies would not be established until after the Hivan War, but the existence of the fleets themselves was an important sign of national independence.
To this day, the possession of a space fleet of any size is the grandest expression of national power possible. All four Great Powers possess space fleets of devastating size and power, and even mid-tier nations like Forthena or the Republic of Man are worthy of respect for their not insignificant presences in the void.