In a fanfiction where Naruto is born during the Second Shinobi War, he could potentially be a major asset to the Leaf Village much earlier. Since he's the jinchuriki of the Nine - Tails, his power could be harnessed for the war effort. However, this also means he'd be in more danger from enemy villages who would want to either capture or kill him. His relationship with the villagers might be different too. Instead of being shunned for the Nine - Tails inside him, they might see him as a necessary evil for the village's survival.
Well, in a fanfiction with Naruto born in the Second Shinobi War, his upbringing would be shaped by the war. Maybe he'd be trained by different people. For example, instead of Iruka being one of his first mentors, it could be a war - hardened ninja who's more focused on making Naruto a killing machine. His view of the ninja world would be more cynical from the start. He might not have the same dreams of becoming Hokage in the traditional sense. Instead, he could be more focused on ending the war and protecting the few people he cares about.
The relationship with the village elders would be complex. They might have seen him as both a great hope and a potential liability. His relationship with the other Jinchuriki could also be different. If he was known earlier as a Jinchuriki, he might have been in contact with others, like Gaara, earlier. And his relationship with Sasuke would have an added layer. Maybe Sasuke's family would have seen Naruto in a different light, knowing he was born before the war and had some sort of special significance.
If Naruto was born before the Second Shinobi War, the story would be drastically different. For one, the political landscape of the ninja world at that time was very different. There were different power struggles and alliances. Naruto might have grown up in a more chaotic and war - torn environment. His presence could have potentially changed the outcome of some of the battles during the Second Shinobi War. Maybe he could have influenced some of the key players in a way that would lead to a different future for the ninja villages.
Well, in a fanfiction where Naruto is born before the Third Shinobi War, it could mean that the prophecy about him might have been known earlier. This could have led to different training methods for him. Maybe the Sannin would have been more involved in his upbringing. Jiraiya could have started training him much earlier, and Tsunade might have been more focused on his physical well - being. Orochimaru, on the other hand, might have seen him as an earlier opportunity for power and tried to manipulate him much sooner. All these changes would have a huge impact on the overall Naruto storyline.
If Naruto was born during the Second Shinobi War in fanfiction, he might have more battle - hardened powers. He could potentially have a better control over the Nine - Tails' chakra from a younger age due to the need to fight in the war. His Rasengan could be developed in a more combat - oriented way, perhaps with added elements of destruction to take on stronger enemies.
One implication could be that Naruto grows up in a more war - torn environment. He might see more death and destruction from an early age, which could make him more determined to end wars. For example, he might witness the pain of orphans like himself on a much larger scale, fueling his desire for peace.
His relationship with Iruka could be more intense. Iruka, who has also lost a lot during the war, might see Naruto as a chance to heal his own wounds. He could be even more nurturing towards Naruto from the start.
In a fanfiction scenario where Naruto starts the 4th Shinobi War, it would completely change the whole Naruto universe's narrative. Naruto is known for his desire for peace, so if he starts the war, it might be due to some extreme manipulation or a misunderstanding of the situation. For example, he could be tricked by an enemy who has disguised themselves as an ally and convinced Naruto that starting the war is the only way to protect the Leaf Village. This would lead to a situation where all his friends and comrades would be forced to either oppose him or be dragged into a war they didn't want.
In some fanfictions, if Naruto was sent to the Third Shinobi War, he could change the course of many battles. His unique jutsus like the Rasengan might surprise the enemies. He could also inspire his comrades with his never - give - up attitude.
Potential allies? Well, Jiraiya for sure. Jiraiya was always interested in unique and powerful ninja. If Naruto was born earlier, Jiraiya would likely be drawn to him. And maybe some of the members of the Uzumaki clan who were still alive at that time. They could have guided Naruto in using his clan's unique abilities. Enemies? The Akatsuki could have emerged as enemies much earlier. Their goals were often in conflict with the stability of the ninja world, and Naruto, with his powerful potential, would be a target for them.
He could meet the young Hiruzen Sarutobi. Naruto might learn a lot from him about the history and politics of the shinobi world at that time. They could also exchange jutsu knowledge to some extent.