Here's The list of open countries.
Axis Powers
North Italy
Germany[on hold]
Japan
Allied Forces
America
England
France
Russia
China
West Europe
Belgium
Netherlands
Central Europe
Austria
Hungary
Liechtenstein
Poland
Switzerland
Eastern Europe
Belarus
Estonia
Latvia
Lithuania
Ukraine[on hold]
Nordics
Denmark
Finland
Iceland
Norway
Sweden
Mediterranean Europe and North Africa
Egypt
Greece
Monaco
Turkey
South Italy
Spain
Asia
Hong Kong
Taiwan
South Korea
Veitnam
North America
Canada
Cuba
Micro-nations
Sealand
Seborga
Wy
Turkish Republic of Northern Cyprus
Others
Prussia
Seychelles