Background
Li Jue and Guo Si had originally been subordinate commanders under Dong Zhuo. After Dong Zhuo's death they joined forces to counterattack and seize Changan, dominating the court and creating the bloody chaos that engulfed Changan from the Xingping era into the early Jian'an years. After Emperor Xian made his way back east to Luoyang, the court had escaped their direct grip, but the remnant forces in the Guanzhong region continued to occupy various commanderies — neither submitting to the court at Xudou nor ceasing to harass the local population. Duan Wei had long garrisoned Huayin, maintaining an equivocal relationship with Li Jue and Guo Si in terms of political alignment; his position happened to straddle the vital corridor leading east from Changan through Hangu Pass. Once the Emperor Xian's political system had re-established its footing from Xudou, the moment to finally extirpate the remnant forces of Li and Guo had at last arrived.
Course of Events
According to the account in chapter seventeen of the novel, in the fourth month of summer in the third year of Jian'an, as Cao Cao was leading his army back to the capital, the Guanzhong commanders coordinated their actions: Duan Wei dispatched troops to attack Li Jue directly, capturing and executing him along with more than two hundred members of his clan, then forwarding his troops to Xudou; Guo Si was assassinated in his own camp by his trusted subordinate Wu Xi, and both men's severed heads were presented together to the court. This mode of "attack from within against those without" minimized the court's need to send its own forces directly while shifting the costs of post-war political reconstruction onto the Guanzhong commanders themselves, allowing the power vacuum east of Changan to be filled rapidly.
Outcome
Emperor Xian convened a grand assembly of civil and military officials at the palace in Xudou and issued the order for the remaining followers of Li Jue to be executed at each of the city gates, with their heads displayed as a warning to the people, who rejoiced at the news. Duan Wei was enfeoffed as General Who Crushes Bandits, Wu Xi as General Who Eliminates Insignificance, and each was permitted to lead his old troops and remain as garrison in Changan. This was the first time the Han court, under Cao Cao's control, conducted a systematic "settling of accounts" with the Guanzhong warlords in the name of the center — marking the political epilogue of the Liguozhiluan. Cao Cao immediately followed with a memorial requesting to campaign against Zhang Xiu, and Emperor Xian personally saw the army off; the event is anchored to the fourth month of summer in the third year of Jian'an. In the short term the Changan front was stabilized, allowing Cao Cao to turn his full attention to the Nanyang and Xuzhou directions.
Significance
From the perspective of the novel's narrative structure, this event serves three closural functions. First, it brings to an end the Guanzhong disorder that had continued for nearly seven years since Dong Zhuo's death, allowing the novel's middle section to enter the clear main plotline of "heroes competing for supremacy." Second, it absorbs Guanzhong veterans like Duan Wei and Wu Xi into Caowei service through a system of "using disorder to pacify disorder," reflecting Cao Cao's long-term methodology toward local armed forces: first recognize their existing positions in exchange for loyalty, then reorganize once central power is sufficient. Third, Emperor Xian personally seeing Cao Cao off on campaign elevates the legitimizing ritual of "holding the Son of Heaven hostage to command the regional lords" to a new height in literary terms, laying the groundwork for the Wancheng and Guandu storylines to come. From a longer perspective, Guanzhong after the Li-Guo disorder actually entered a state of near-vacuum; it would not become a major battlefield again until Cao Cao's late years and the Battle of Tongguan against Ma Chao and Han Sui — the political stability in between rested on the thin order provided by proxies like Duan Wei and Wu Xi, which was precisely the foreshadowing of Guanzhong's long-term defensive weakness.