Itachi Would Have Killed Hebi Sauske If he Tried

Sasuke: It's nonsense. He tried to kill me over and over.
Tobi: If Itachi had really wanted to kill you .... you would most most certainly be dead.
Sasuke: He used the Mangekyo Sharingan on me. So...
Tobi: Even your contingency plans were part of his calculations. Itachi had to pressure you during that battle.
Sasuke: .....!
Tobi: I'm sure you already understand why?