There's an argument on the tip of Bucky's tongue, that this place doesn't need anyone to carry the shield -- that the dangers Captain America is typically called upon to fight simply don't exist here with any regularity -- but he doesn't say it, because he doesn't believe a damn word of it himself. Moreover, it doesn't actually fix their problem; even if it never gets used, someone needs to take it.

Things have changed for Bucky since Steve last asked this of him; his identity's been leaked to the press, he's been stripped of the flag, he apparently gets sentenced to a stay in a gulag... And yet, despite all that, there's a part of him that wants to prove himself to Steve, wants to impress his old partner, to show that while he's not a good man, he still tries. What he wants is not the shield or the mantle, but rather, the opportunity they represent for him to earn this life that's been given. He holds Steve's gaze, not shying away from the situation as might be his inclination otherwise, and lets out a sigh.