Declaration of War (Naruto episode)

is episode 205 of the Naruto: Shippūden anime.

Summary
Naruto thinks of Madara's words about Sasuke. Madara arrives at the summit room and teleports Sasuke, then Karin to a safer location. Madara then reveals the origin of the tailed beasts, as the Ten-Tailed Beast. He reveals that his plan is to revive the Ten-Tails and become its jinchūriki, and then cast an infinite Tsukuyomi on the moon giving him control over everyone on the planet. Madara asks the Kage to hand over the remaining tailed beasts. When they refuse, Madara declares the Fourth Shinobi World War, and leaves. The Kage agree to the formation of the Allied Shinobi Forces. Sakura arrives at Naruto's location, and wants to tell him something.