From the perspectives of the Galactic Republic and the Jedi Order, the Nihil conflict, also referred to as the war against the Nihil or the war with the Nihil, was a conflict that transpired in the galaxy during the High Republic Era. This conflict pitted the Republic and Jedi against the Nihil, a band of lawless marauders originating from the Outer Rim. The actions of the Nihil varied from small-scale engagements to the complete pillaging of entire planets.
The conflict's origins can be traced back to 232 BBY, following the Great Hyperspace Disaster, a terrorist act masterminded by Marchion Ro, the Eye of the Nihil. The Nihil justified their actions by claiming that the Republic was infringing upon their freedom and denying them representation within the Galactic Senate, leading them to defend their way of life. The Nihil posed a significant threat due to their access to mysterious routes known as "Paths," which defied the established principles of hyperspace travel. While the Battle of Kur initially suggested the Nihil's defeat, they demonstrated their continued existence by destroying the Valo Republic Fair.
Ultimately, the Jedi Order was able to force the Nihil to disperse. However, in 230 BBY, the Nihil successfully prevented the Galactic Republic from accessing ten entire sectors within the Outer Rim Territories, effectively claiming that territory for themselves. Subsequently, Ro issued a broadcast to the entire galaxy, publicly revealing his identity.
In the Frontier, before the Nihil were widely recognized as a threat, Ro orchestrated the Emergences. While the Jedi and Republic focused on responding to these Emergences, Ro launched attacks on several planets, including Trymant IV and Elphrona. During the assault on Trymant IV, Ro abducted Elder Tromak and Krix Kamerat of the Elders of the Path. Kamerat would later align himself with Ro. The Nihil also destroyed a Republic diplomatic vessel, the Steady Wing, leaving four young individuals stranded: Jedi Vernestra Rwoh, Padawan Imri Cantaros, aspiring scientist Avon Starros, and Honesty Weft. Ro commanded his forces to raid the planet Elphrona, intending to take the Blythe family as hostages. However, the family managed to send a distress signal to the Jedi on Elphrona before being captured. The Jedi arrived to find the family missing and the Nihil had booby-trapped the area with mines. After disarming the mines, the Jedi pursued the Nihil kidnappers, rescuing the Blythes one by one until only Ottoh Blythe remained. Jedi Master Loden Greatstorm boarded the Nihil ship holding Blythe, but his leg was broken during the attempt. Tempest Runner Lourna Dee then arrived, capturing both Greatstorm and Blythe and delivering them to Ro. Ro revealed that his true objective was to capture a Jedi, and he subsequently killed Blythe.
The Galactic Republic, with the assistance of the Jedi, retaliated against the Nihil at the Battle of Kur, initially believing they had achieved victory. However, the Nihil proved their continued existence by attacking and destroying the Valo Republic Fair. Following this attack, the Republic and the Jedi jointly launched Operation: Counterstrike, a series of coordinated retaliatory strikes that scattered the Nihil forces. Historian Beaumont Kin later observed that the Republic's response to the Nihil threat was inadequate until significant time had passed and civilian casualties had occurred.
After the destruction of Starlight Beacon, Marchion Ro, broadcasting from his flagship, the Gaze Electric, publicly announced himself to the galaxy and the Republic, declaring his control over the galaxy. The Nihil established a region of space known as the Occlusion Zone, isolating it from the Republic using the Stormwall. The Nihil continued their raids outside the Stormwall, exploiting their unique hyperdrives that could penetrate it. Consequently, acquiring a Nihil hyperdrive became a high priority for the Republic, as it would grant them the ability to bypass the Stormwall. Nine months after the destruction of Starlight Beacon, Jedi Knights Bell Zettifar and Burryaga joined Grand Master Pra-Tre Veter and the RDC to assist the planet of Asternin, which had been attacked by the Nihil. Upon their arrival, the Nihil returned, led by Melis Shryke, who used a Lightsaber nullifier to disable the Jedi's lightsabers. Veter ordered Zettifar and Burryaga to evacuate the nearby settlement while he confronted the Nihil. Veter was captured while trying to reach Shryke.
As the RDC started constructing a base on Eriadu, a planet relatively safe but still close to the Stormwall, a Nihil ship that appeared to be abandoned was discovered. Joss Adren, concerned that Eriadu was not entirely safe from the Nihil, and Pikka Adren were sent to the ship to retrieve its hyperdrive. However, they found two life signs on board. Their ship, the Aurora III, was then deactivated while they were calling for backup.
In the end, the Nihil lost their power and were defeated. In 200 BBY, the Jedi Padawan Sean remembered the Nihil as an illegal group that once invaded the Galactic Republic. In his book The Rise and Fall of the Galactic Empire, Kin considered the Nihil conflict as one of the failures of the High Republic government. However, he still admired the High Republic Era because it was a time when the galaxy worked together against a common enemy.