Shortly after this, war soon broke out between the two factions. Both the OT and PT were made to reflect currrent times with their events. I think its more to do with generational differences.

The Clone Wars was a puppet war, the Galactic Civil War was a war for freedom. The New Mandalorian government did not want to go to war with the Death Watch, though by 2 BBY it became clear that it seemed inevitable and so in response they had the charismatic Journeyman Protector Jaster Mereel assemble a team of fellow Protectors loyal to him in order to create a group of supercommandos. They turned sand into starships, fear into a fire, hope into victory. Skilled but undisciplined, these soldiers rallied to Vizsla and formed a splinter group that came to call itself the Death Watch. In particular were the followers of the barbaric Mandalorian soldier Tor Vizsla, who dreamed of a goal opposite of the New Mandalorians: a return to the ways of the ancient Mandalorians as raiders and conquerors, aiming to eventually wage a second war of conquest across the galaxy. However, not all would agree with the New Mandalorians reforms. They used their talents as builders and inventors to create grand cities in Mandalore's desert and operated under a separate government out of their capital city of Sundari on the planet they deemed 'New Mandalore.' Star Wars is the epic space opera created by George Lucas. The Star Wars story follows the story of the creation of the Galactic Empire, the Galactic Civil War, and the disolving of the Empire and its affiliates. Instead, the New Mandalorians preached peace, neutrality, and tolerance. The first film was released in 1977 and the last episode is set to release in 2019 or 2020. This reformist political faction formed from the remnant of the pre-Excision peace movement renounced violence and the warrior codes of Mandalore's past, in what they believed to be an effort to save Mandalore and survive in a hostile galaxy. After being devastated in a large-scale assault by the Old Republic, which transformed parts of Mandalore into inhospitable deserts of white sand, a pacifist sect calling themselves the New Mandalorians arose from the disaster.

The origins of the conflict could be traced back to the fallout at the end of the Clone War.

How long was the galactic civil war