Fourth Shinobi World War

The beginning of the was declared by Madara Uchiha when the five Kage refused to give him the Eight-Tailed Giant Ox and the Nine-Tailed Demon Fox for his Eye of the Moon Plan. Madara has stated that he will use the seven tailed beasts already captured by the Akatsuki in combating the ninja world. The Fifth Kazekage, the Fifth Mizukage, the Fourth Raikage, the Third Tsuchikage, and General Mifune have agreed to form a Shinobi Alliance, pooling their resources against Madara. The daimyo of the Five Great Shinobi Countries and the Fifth Hokage later join the alliance as well.

Preparations for War
Thus far both sides are gathering their strength and collecting information about the other side in preparation for the upcoming hostilities. Kisame continues to gather intelligence on Kumogakure's military strength and on Killer Bee traveling with him everywhere while hidden inside Samehada. The team of Anko Mitarashi tracks Kabuto Yakushi, which led them to Madara Uchiha's lair. Other Shinobi Alliance teams have fanned out to collect other information about Akatsuki and their hideouts.

Kabuto has formed an alliance with Madara, showcasing his use of the Summoning: Impure World Resurrection technique, increasing the forces of Akatsuki with the resurrection of dead members of the organization. The Five Kage have decided to hide the two remaining jinchūriki, Naruto and Killer Bee in a island in the Land of Lightning. Hiding Killer Bee and Naruto had the unintended result of allowing Naruto to learn to control the Nine-Tailed Demon Fox's chakra, much like the way Killer Bee has of the Eight-Tailed Giant Ox. Having been successful in his training, Naruto has exhibited increased speed and strength when utilizing the controlled chakra of the Nine Tails.

Despite being captured in the end and committing suicide to keep the information he held secret, Kisame was able to finish Akatsuki's preparations for the War by sending a summon shark with a scroll to his comrades.

Both the Allied Shinobi Forces and Akatsuki have amassed considerable forces for this war, 80,000 shinobi and samurai total make up the Alliance and 100,000 Zetsu clones and at least 24 warriors of note revived by Kabuto make up Madara's army. The first large scale battle between the two forces seems to be on the horizon, and Madara had dispatched Kabuto to retrieve the Nine-Tails and Eight-Tails, with Ōnoki going to reinforce the forces on the Island Turtle and was able to stop Kabuto, but Kabuto still made it out with Yamato, intending on strengthing the Zetsus with Yamato's powers.

Allied Shinobi Forces
The Allied Shinobi Forces created by the Five Great Nations and the Samurai if the Land of Iron consists of five main divisions, with Gaara of the Sand as the Commanding General. The 1st Division consists of midrange fighters and is led by Darui. The 2nd Division is made up of Close Range Fighters and is led by Kitsuchi. The 3rd Division is under the command of Hatake Kakashi, and features both close and midrange fighters. The 4th Division contains only long range fighters under the control of Gaara, who is also the commanding general of the entire army. Shikamaru is Gaara's right hand man and proxy general of the 4th division as well. Finally, the 5th division was created for the purpose of special operations, and features ninjas with unique skills. Mifune is the leader of these special operatives. There is also four special company formed for the war. The Medical Logistics Company led by Shizune comprises of medical ninja, the Ambush Company led by Kankurō, has the task to ambush the enemy forces. The second is the Sensor Company with Ao as captain, and finally the Intelligence Company headed by Inoichi Yamanaka.

Akatsuki
Akatsuki, run by Madara Uchiha, has evolved since its first introduction. Its second in command in Kabuto Yakushi, and operate out of a base to the north. There are three living members: Madara, Kabuto, and Zetsu. However, Zetsu has 100,000 clones ready for battle, which were somehow created using Hashirama Senju's power. Kabuto also has taken from Orochimaru the Summoning: Impure World Resurrection technique, and has used it to resurrect at least 21 known shinobi, who are as follows:

Attack on Hachibi

 * Akatsuki Parties Involved
 * Kisame Hoshigake
 * Zetsu


 * Allied Shinobi Forces Parties Involved
 * Sabu
 * Killer Bee
 * Fourth Raikage

While Bee was training in rap with Sabu, Kisame tracked them down and attacked. Bee easily countered all of Kisame's attacks, and then ended up destroying Kisame's midsection with a partial-jinchuuriki form. In order to heal his wounds, Kisame fuses with Samehada, and becomes a shark-like creature. He then summoned an enormous ball of water in which he trapped Sabu and Bee. Bee figured that since he was whom Kisame was after, he could swim away from Sabu to save the man. However, and Bee swam away, he saw Kisame headed straight for Sabu. Bee doubled back to save his mentor, and Kisame revealed that it was just a ploy to draw Bee in close, and proceeded to attack. Kisame then dissipated the dome, and came apart from Samehada, his wounds having healed. He attempted to remove Bee's legs with Samehada, but the sword refused, and ended up giving chakra to the jinchuuriki. Kisame then kicked Samehada far away, and attempted to cut Bee's legs off with one of Bee's own swords. Bee, having been given chakra, was able to respond by throwing a lightning-infused pencil at Kisame before he could attack. This narrowly hit Kisame on the side of the head, grazing him. A then arrived with Ao and Darui, and A and Bee then attacked with a lightning-fast Double Lariat. This decapitated Kisame, and ended the battle.

However, unknown at the time to the Allied Shinobi Forces, Kisame was actually a Zetsu clone, and Kisame was hidden inside Samehada, infiltrating the enemy's borders because Bee took the sword with him.


 * Outcome: Apparent Allied Shinobi Forces Victory

Kisame Ambush

 * Akatsuki Parties Involved
 * Kisame Hoshigake


 * Allied Shinobi Forces Parties Involved
 * Killer Bee
 * Naruto Uzumaki
 * Might Guy
 * Yamato
 * Motoi
 * Aoba

Kisame was hiding inside of his sword, Samehada, when Naruto discovered him. The sword was currently in the possession of Killer Bee, and Kisame burst forth. He held information about the jinchuuriki on Island Turtle. Might Guy immediately confronted the former Kirigakure ninja, and forced himself to open seven gates in order to perform Daytime Tiger. He rendered Kisame unconscious, and Aoba proceeded to attempt to gain information from him. Kisame forced himself awake, however, and burst out of the stocks he had been placed in. He then cast his Water Prison Technique, and sealed himself inside. He then summoned three sharks, which consumed the ninja. He committed suicide in order to prevent the enemy from gaining any information on Akatsuki.


 * Outcome: Decisive Allied Shinobi Forces Victory, 1 KIA (Akatsuki)

Battle for the Rinnegan

 * Akatsuki Parties Involved
 * Madara Uchiha


 * Allied Shinobi Forces Parties Involved
 * Konan

Madara Uchiha confronted Konan within Amegakure, in search of Nagato's corpse and the Rinnegan. Konan had prepared for the battle, having integrated explosive tags into her body as well as placing 600 billion of them into her Paper Person of God Technique. Madara underestimated her prowess, losing an arm and part of his mask while she took advantage of his 5-minutes limited of intangibility with 10 full minutes of explosion. When Konan thought she had won, Madara surprised her with his Izanagi to escape her technique, and he used a genjutsu to get the location of Nagato from her, then killing Konan and retrieving the Rinnegan.


 * Outcome: Decisive Akatsuki Victory, 1 KIA (Allied Shinobi Forces)

Battle of Island Turtle

 * Akatsuki Parites Involved
 * Kabuto Yakushi
 * Deidara


 * Allied Shinobi Forces Parties Involved
 * Yamato
 * Aoba
 * Motoi
 * Kurotsuchi
 * Akatsuchi
 * Third Tsuchikage

The jinchuuriki were confined to Island Turtle, a living island off the coast of Kumogakure, after the declaration of war. Madara sent Kabuto and Deidara after them, with the task of securing the two jinchuuriki. The Tsuchikage, Akatsuchi, and Kurotsuchi intercepted the pair on their way to defend the island, and Deidara decided to take on the Tsuchikage by himself and draw him away from the island. Akatsuchi stayed back to aid the Tsuchikage, but Kurotsuchi pursued Kabuto to the island.

Yamato, Motoi, and Aoba left the inner part of the island to see what was happening, and ended up encountering Kabuto at the same time as Kurotsuchi. Kurotsuchi then used her Lava Release: Quicklime Congealing Technique in conjunction with Water Release: Water Trumpet to trap Kabuto. Yamato aided Aoba to approach Kabuto, with the intention of obtaining information. However, Kabuto revealed that his body had transformed into a snake as he burst from his body. He bypassed Aoba and slithered straight for Yamato, capturing him in his mouth.

Deidara and the Tsuchikage were locked in a stalemate, though Deidara was preparing to use a powerful move. However, before he could unleash it, Kabuto recalled his body and retreated with Deidara back to Madara's hideout, with Yamato as a prisoner of war.


 * Outcome: Akatsuki Retreat, 1 POW (Allied Shinobi Forces)

Trivia

 * Itachi Uchiha prevented an earlier potential outbreak of a Fourth Ninja War by carrying out the Uchiha Clan Massacre.
 * The Fourth Ninja War was also declared by Hiruko in the third Naruto Shippūden Movie, and would have pushed through if not for the efforts of select Konoha shinobi.