Is the one between Korea and Sealand the Vatican?

Nope. TV Tropes and Wikipedia seem to indicate it's the Principality of Seborga: http://en.wikipedia.org/wiki/Principality_of_Seborga

who's the one behind sweden?

white-devil said:
who's the one behind sweden?

Seychelles

Holy crap, I just realized how frighteningly similar Hetalia's Sweden looks to Scandinavia and the World's Sweden.

Just ruffle the hair a bit and presto!

Wait, but who's that behind America?
And where's Kumajirou?

NeoChaos said:
Nope. TV Tropes and Wikipedia seem to indicate it's the Principality of Seborga: http://en.wikipedia.org/wiki/Principality_of_Seborga

Thanks. Just saw him two days ago.

the order of the allies of ww2?

VocaUtau said:
Wait, but who's that behind America?

Canada. The flag-patterned bubble pointing to him should've made that obvious. As for Kumajirou, I can only guess a artist oversight.

NeoChaos said:
Canada.

Who?