Star Wars: Birth of the Republic
When the Duros discovered Alderaan, colonized by Coruscant generation ships centuries ago but now completely distinct from Coruscant by virtue of being unable to communicate with them since arrival, they happily shared the secret of the hyperdrive for a small fee, and Alderaan soon joined the free worlds in the Battle of Kuat. Though they had little to contribute as a peaceful planet opposed to wars except in the most dire of situations, Alderaan fought against the Infinite Empire until they were routed at the Battle of Coruscant and fled to a hidden base.
Alderaan has strong diplomatic ties with all worlds. Even the Azure Imperium, normally intensely xenophobic, remains on decent terms with Alderaan, enjoying a healthy trade relationship and an otherwise unheard of exchange of embassies. Alderaan has been the premier proponent of the creation of a longterm alliance between the free worlds, and as part of this, some formal method of resolving disputes besides war. The noble houses of Alderaan have resolved disputes by council for generations and thus have not seen any war besides that with the Rakata in all of living memory. This is seen by Alderaan as proof of concept for a great galactic alliance that could someday lay to rest all war throughout the galaxy. More immediately, it might prevent war between the Azure Imperium and Alsakan, or stop Coruscant and the Duro Kingdom from going to blows, or prevent Corellia from attacking Coruscant, the Azure Imperium, or both for being “imperialists,” or any of a number of other potential conflicts that could explode into open warfare any day.