To quote the general himself, "If it's right at the top, it's right at the bottom."
Inchon was brilliant, but it was negated by his stubborn refusal to accept the reality presented to him by his intelligence officers that a half million Chinese were surrounding our troops.
https://en.wikipedia.org/wiki/Edward_Almond
The China intervention was a screw up by Almond dispersing X Corp.
And as the General on the ground he was telling MacArthur in Tokyo not to worry about the Chinese.