Sasuke, listen to me. He didn't betray Konoha. No... far from it. He was a hero who died for his village. He carried out his mission knowing full well what was going to happen.
Self-sacrifice... because that was his duty.
Itachi's defection was a ruse set up by the Konoha government. It was all a big drama staged by Konoka so they could get their hands on the Kyubi's Legacy.
And Itachi was the star of the show. Only a legendary hero like Itachi could have earned Madara's trust.
But the public couldn't be allowed to find out about it... not ever. This, they concluded, would be the best way to keep the whole thing under wraps. Itachi wouldn't be allowed to come back home alive. And he wouldn't be allowed to kill himself. His life would be ended by his most beloved brother... That was the way the government wanted it. That was the mission he was given. And he had no choice but to carry it out. His death at your hands was duty he had to fulfill. Out of duty, he turned his back on his own comrades. A lesser man would have been crushed by such a burden.
The taint of disgrace will follow him to his grave. Future generations will revile him in Konoka as a despicable traitor with no sense of honor. He will go down in official history as a war criminal. And no one will ever understand him. That... was his final mission. And like a true soldier, he saw it through to the end.
But I think he wanted you of all people to know the truth. He wanted to live on in your memory. Not as a ninja, but as a brother. But he was forbidden to tell you himself. And that's why he told me.
Sasuke, history will never know what he did. No one will ever learn the truth. His story... his debriefing... will endure only in your heart. Everything he did, he did for his country. He sacrificed his life and his honor for his native land. He was a real hero.
He was a true ninja.