At first, even with his firm determination and telling himself it's okay, he isn't able to do much of anything as he's grabbed by the throat. He chokes, feet kicking as he's held higher. His free hand reaches to try and pry himself free, but it's not working, and even with his sword in his hand he doesn't want to hurt America. He doesn't want to kill him!

Then America's words reach his ears. He has to do something. Maybe it's the urgency that causes his quick thinking, either in America's words or his own mind as he's quickly losing the ability to hold on much longer. Whatever it is, he has an idea, and he's received enough instruction from America to decide he can go for it. If he has to make up for it later, then so be it!

"F-forgive me..."

With that, he raises his sword in a quick and harsh swipe. Not at America's stomach, though it may have seemed to be the most obvious thing, but to cut off that hand that's choking him.