In a fanfiction scenario where Naruto starts a war, it could be due to a personal vendetta against a certain group. For example, if a group of rogue ninjas were responsible for the death of someone he loved dearly, like Jiraiya. Naruto's anger and grief could drive him to wage war against all those associated with that group, regardless of the consequences for the larger shinobi world.
Well, one possibility could be that Naruto is somehow influenced by a dark force. Maybe he discovers some dark secrets about the shinobi world that make him believe war is the only way to bring about true change. He might start by attacking the Five Great Nations, thinking he can overthrow the existing power structures and create a new, more just world.
Perhaps Naruto starts a war because he's been misled. He could be tricked into believing that another village is planning a massive attack on Konoha and all of its allies. In his haste to protect his home and friends, he launches a preemptive strike, which then spirals into a full - scale war as other villages retaliate.
Chapter 891, "If You're a Man, Keep Drinking!", is the clearest early answer because it turns Shen Lan's situation into a concrete plot event. The chapter turns that into something concrete by moving from Jiang Yan couldn't bother to coax these two little brats anymore.
The best chapter pointer here is Chapter 1, "I'm Not Interested in Uncultured Men". It opens with Jiang Li, I'm warning you, don't set your sights on Yinwan anymore, or... and closes on Yet before she had the chance to teach her a lesson, the male lead arrived....
Look to Chapter 11 for the clearest answer. It begins with After a meeting, Shang Shaojing pinched the bridge of his nose, tired, and..., keeps building through How is it going with the Jiang Family?" The assistant looked troubled and..., and lands on Miss Qin, please accompany us to the police.
Chapter 590, "Are You Angry?", is the clearest early answer because it turns Miss Jiang's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Night had completely fallen, and a chill hung in the air over Dragon...
Chapter 616, "I'm Going to Save Sister Xiao Wan!", is the clearest early answer because it turns Su Yinwan's situation into a concrete plot event. Early on, Since the storm had hit that morning, he had been preoccupied and out....
Chapter 808, "Dare to Spank Him?!", is the clearest early answer because it turns Jiang Bufan's situation into a concrete plot event. Early on, I don't listen, I don't listen," Jiang Bufan once again started his.... By the end, I...." Just then, Jiang Bufan started wailing even louder, even....
Chapter 896, "Are You a Male Model?", is the clearest early answer because it turns Male Model's situation into a concrete plot event. It opens with Upon hearing this, Wen Jiaojiao seemed to think of something and...
Chapter 631, "It's Him Who Got Hurt, Then It's Fine", is the clearest early answer because it turns Hurt's situation into a concrete plot event. Early on, To avoid making a disturbance, the next second, Zhao Lang directly....
Chapter 712, "This is definitely not reliable!", is the clearest early answer because it turns Jiang Mingyu's situation into a concrete plot event. The chapter turns that into something concrete by moving from Exactly, exactly." Wen Jiaojiao said discontentedly, her arms crossed.
Chapter 657, "The Richest Man Becomes a Hardcore Fan?!", is the clearest early answer because it turns Boss's situation into a concrete plot event. It opens with Zhao Lang had arrived in the Capital in the early hours of the...