The Fourth Shinobi War represented a major shift in the world of Naruto. For the first time, all Five Great Shinobi Countries and the Land of Iron formed an alliance. Years of war and conflict had been set aside for the greater good of the world. The possibility for lasting peace seemed like it could be finally be achieved. But noticeably, Amegakure, the Village Hidden in the Rain, was missing from that alliance.
After the deaths of Amegakure's leaders, Nagato and Konan, the village was largely ignored for most of the war and the rest of the series. The absence of Amegakure is honestly a disappointment. Their inclusion in the alliance and the war would have aided in defeating the Akatsuki army and also would have reinforced the themes of that arc. Amegakure could have helped lead the world into a new era of peace instead of being forgotten in the chaos.
Like many other villages in the world of Naruto, Amegakure knows firsthand the destruction that war and violence can cause. Amegakure has probably suffered more than most other villages since it's surrounded by three of the Five Great Shinobi Countries. During the Second and Third Shinobi Wars, Amegakure was used as a battleground, turning most of its population into war refugees. Out of all the villages, Amegakure has the most reason to mistrust the other countries. This would have made their inclusion in the alliance all the more powerful. Amegakure would have shown a willingness to let go of its grudges for the betterment of the world and a chance at peace.
The Akatsuki was created in Amegakure during the Third Shinobi War. The organization was originally a pacifist group whose only goal was to end the war ravaging their country. However, due to the death of the Akatsuki's first leader Yahiko by Amegakure's previous leader Hanzo and manipulation from Obito and Black Zetsu, the group became corrupted. The Akatsuki set aside their peaceful ways and began recruiting criminals to help them in their goals. It would have been interesting to see the shinobi of Amegakure take responsibility for the group created in their village.
If Amegakure had joined the Allied Shinobi Forces, it would have fulfilled the last wishes of their previous leaders Nagato and Konan. Although Nagato was originally an enemy and attacked Konoha, he eventually decided to put his trust in Naruto. Nagato sacrificed his life to fix the damage he caused and support Naruto's goals. Konan similarly put her faith in Naruto and abandoned the Akatsuki. Konan died fighting Obito and promised to support Naruto on his path to peace. The last wishes of both leaders of Amegakure were to aid Naruto in his mission for world peace.
The shinobi of Amegakure viewed Nagato as a "god" and Konan as his "angel." Amegakure's shinobi were very loyal to Nagato and Konan. It would have created a powerful moment if the shinobi decided to honor their leader's last wishes and join the alliance in order to protect Naruto. This would have given Konan's death more significance. She promised to support Naruto but died before she could really aid him. If the Amegakure shinobi had joined the war, it would have been like Konan was fulfilling her promise from beyond the grave.
As it stands now, Amegakure is largely in ruins and without a leader. Just like during the Second and Third Shinobi War, Amegakure was treated as insignificant and left to rebuild itself with no support. If Amegakure had joined the alliance, the other villages could have seen the dedication of their shinobi and might have been moved to assist them after the war. Amegakure could have grown in strength and eventually joined the other villages as a world superpower. After years of conflict, neglect and manipulation, Amegakure deserves respect and to have its importance recognized.
