"Future and Past" (未来と過去, Mirai to Kako) is chapter 219 of the original Naruto manga.
Sasuke remembers that he and Naruto were interrupted the last time they fought. Intending to settle that contest, Sasuke attacks him. He is impressed by the power granted to him by his newly-evolved cursed seal and concludes he has made the right choice by defecting to Orochimaru. Naruto counterattacks in an effort to bring Sasuke back to his senses. Sasuke claims to have always been quite aware of what he was doing, even when he was wasting his time in Konoha. He is not driven by future possibilities, his actions determined by his past with Itachi.