There’s no such thing as “national sin”. There are only the sins of individuals and Jesus died for ALL the sins of the WHOLE world (John 1:29; 1 John 2:2).
You're the one who alluded to it, no you're saying there's no such thing?
Actually....
And these are all future prophecies too.
Psalm 110:6
He will judge the nations, heaping up the dead and crushing the rulers of the whole earth.
Joel 3:12
Let the nations be roused and advance into the Valley of Jehoshaphat, for there I will sit down to judge all the nations on every side.
Micah 4:3
Then He will judge between many peoples and arbitrate for strong nations far and wide. Then they will beat their swords into plowshares, and their spears into pruning hooks. Nation will no longer take up the sword against nation, nor will they train any more for war.
Matthew 25:32
And before him shall be gathered all nations: and he shall separate them one from another, as a shepherd divideth his sheep from the goats:
Nations, city-states and entire peoples have been judged so there I'll just have to disagree with you. I'll toss out four examples: Nineveh, Sodom and Gomorrah and the Canaanites.