It was a choice between going after Makarov, and saving you. The choice could be life or death—for you—for dozens of other people.

Yuri couldn't choose; you'd been with him all his career. You were the first to introduce him to the Task Force, the first to talk to him in trainings.

You were his first choice, so why couldn't you be his?

Why did he have to choose between pulling a rod out of your abdomen, or killing what would be his ex-best friend?