[Zhang Fei]

But the lion’s share is held by the central banks of China, Russia and petro-powers.

This is wrong. The lion's share is held by Americans. The lion's share of the foreign-held debt is owned by Japan and China.

[Freedom_Is_Not_Free]

T McGee was talking about agency debt. As you can see from the picture below, Japan does not hold enough agency debt to even be listed. You are correct to the extent that Japan is the #1 holder of US T-Bills, followed by China, IIRC.