World War I

Countries Involved in World War 1 (WWI)

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Country
World War I Alignment
Year Entered WWI
India Flag
IndiaAllies1914
China Flag
ChinaAllies1917
Nigeria Flag
NigeriaAllies1914
Russia Flag
RussiaAllies1914
Japan Flag
JapanAllies1914
Egypt Flag
EgyptAllies1914
Vietnam Flag
VietnamAllies1914
United Kingdom Flag
United KingdomAllies1914
France Flag
FranceAllies1914
South Africa Flag
South AfricaAllies1914
Kenya Flag
KenyaAllies1914
Myanmar Flag
MyanmarAllies1914
Uganda Flag
UgandaAllies1914
Algeria Flag
AlgeriaAllies1914
Canada Flag
CanadaAllies1914
Angola Flag
AngolaAllies1914
Morocco Flag
MoroccoAllies1914
Malaysia Flag
MalaysiaAllies1914
Mozambique Flag
MozambiqueAllies1916
Saudi Arabia Flag
Saudi ArabiaAllies1915
Madagascar Flag
MadagascarAllies1914
Ivory Coast Flag
Ivory CoastAllies1914
Niger Flag
NigerAllies1914
Australia Flag
AustraliaAllies1914
Mali Flag
MaliAllies1914
Burkina Faso Flag
Burkina FasoAllies1914
Malawi Flag
MalawiAllies1914
Zambia Flag
ZambiaAllies1914
Chad Flag
ChadAllies1914
Somalia Flag
SomaliaAllies1914
Senegal Flag
SenegalAllies1914
Romania Flag
RomaniaAllies1916
Cambodia Flag
CambodiaAllies1914
Zimbabwe Flag
ZimbabweAllies1914
Guinea Flag
GuineaAllies1914
Benin Flag
BeninAllies1914
Tunisia Flag
TunisiaAllies1914
Azerbaijan Flag
AzerbaijanAllies1914
Belarus Flag
BelarusAllies1914
Sierra Leone Flag
Sierra LeoneAllies1914
Laos Flag
LaosAllies1914
Serbia Flag
SerbiaAllies1914
Republic of the Congo Flag
Republic of the CongoAllies1914
Singapore Flag
SingaporeAllies1914
Liberia Flag
LiberiaAllies1917
Finland Flag
FinlandAllies1914
Central African Republic Flag
Central African RepublicAllies1914
Mauritania Flag
MauritaniaAllies1914
Ireland Flag
IrelandAllies1914
New Zealand Flag
New ZealandAllies1914
Kuwait Flag
KuwaitAllies1914
Eritrea Flag
EritreaAllies1915
Armenia Flag
ArmeniaAllies1914
Jamaica Flag
JamaicaAllies1914
Lithuania Flag
LithuaniaAllies1914
Gambia Flag
GambiaAllies1914
Gabon Flag
GabonAllies1914
Botswana Flag
BotswanaAllies1914
Lesotho Flag
LesothoAllies1914
Guinea-Bissau Flag
Guinea-BissauAllies1916
Latvia Flag
LatviaAllies1914
North Macedonia Flag
North MacedoniaAllies1914
Trinidad and Tobago Flag
Trinidad and TobagoAllies1914
Timor-Leste Flag
Timor-LesteAllies1916
Cyprus Flag
CyprusAllies1914
Estonia Flag
EstoniaAllies1914
Mauritius Flag
MauritiusAllies1914
Eswatini Flag
EswatiniAllies1914
Djibouti Flag
DjiboutiAllies1914
Comoros Flag
ComorosAllies1914
Reunion Flag
ReunionAllies1914
Guyana Flag
GuyanaAllies1914
Montenegro Flag
MontenegroAllies1914
Malta Flag
MaltaAllies1914
Maldives Flag
MaldivesAllies1914
Cape Verde Flag
Cape VerdeAllies1916
Belize Flag
BelizeAllies1914
Bahamas Flag
BahamasAllies1914
Guadeloupe Flag
GuadeloupeAllies1914
Martinique Flag
MartiniqueAllies1914
Mayotte Flag
MayotteAllies1914
Vanuatu Flag
VanuatuAllies1914
French Guiana Flag
French GuianaAllies1914
New Caledonia Flag
New CaledoniaAllies1914
Barbados Flag
BarbadosAllies1914
Sao Tome and Principe Flag
Sao Tome and PrincipeAllies1916
Saint Lucia Flag
Saint LuciaAllies1914
Kiribati Flag
KiribatiAllies1914
Seychelles Flag
SeychellesAllies1914
Grenada Flag
GrenadaAllies1914
Isle of Man Flag
Isle of ManAllies1914
Gibraltar Flag
GibraltarAllies1914
Saint Martin Flag
Saint MartinAllies1914
Cook Islands Flag
Cook IslandsAllies1914
Saint Barthelemy Flag
Saint BarthelemyAllies1914
Wallis and Futuna Flag
Wallis and FutunaAllies1914
Tuvalu Flag
TuvaluAllies1914
Saint Pierre and Miquelon Flag
Saint Pierre and MiquelonAllies1914
Falkland Islands Flag
Falkland IslandsAllies1914
Tokelau Flag
TokelauAllies1914
Turkey Flag
TurkeyCentral Powers1914
Germany Flag
GermanyCentral Powers1914
Iraq Flag
IraqCentral Powers1914
Cameroon Flag
CameroonCentral Powers1914
Syria Flag
SyriaCentral Powers1914
Rwanda Flag
RwandaCentral Powers1914
Burundi Flag
BurundiCentral Powers1914
Jordan Flag
JordanCentral Powers1914
Papua New Guinea Flag
Papua New GuineaCentral Powers1914
Hungary Flag
HungaryCentral Powers1914
Israel Flag
IsraelCentral Powers1914
Austria Flag
AustriaCentral Powers1914
Bulgaria Flag
BulgariaCentral Powers1915
Lebanon Flag
LebanonCentral Powers1914
Croatia Flag
CroatiaCentral Powers1914
Bosnia and Herzegovina Flag
Bosnia and HerzegovinaCentral Powers1914
Namibia Flag
NamibiaCentral Powers1914
Slovenia Flag
SloveniaCentral Powers1914
Samoa Flag
SamoaCentral Powers1914
Micronesia Flag
MicronesiaCentral Powers1914
Marshall Islands Flag
Marshall IslandsCentral Powers1914
Nauru Flag
NauruCentral Powers1914
Tanzania Flag
TanzaniaMixed1914
Yemen Flag
YemenMixed1914
Ukraine Flag
UkraineMixed1914
Poland Flag
PolandMixed1914
Ghana Flag
GhanaMixed1914
Czechia Flag
CzechiaMixed1918
Togo Flag
TogoMixed1914
Libya Flag
LibyaMixed1915
Slovakia Flag
SlovakiaMixed1914
Georgia Flag
GeorgiaMixed1914
Indonesia Flag
IndonesiaNeutralnone
Ethiopia Flag
EthiopiaNeutralnone
Mexico Flag
MexicoNeutralnone
Spain Flag
SpainNeutralnone
Argentina Flag
ArgentinaNeutralnone
Venezuela Flag
VenezuelaNeutralnone
Netherlands Flag
NetherlandsNeutralnone
Sweden Flag
SwedenNeutral1914
Switzerland Flag
SwitzerlandNeutral1914
El Salvador Flag
El SalvadorNeutralnone
Norway Flag
NorwayNeutral1914
Equatorial Guinea Flag
Equatorial GuineaNeutralnone
Western Sahara Flag
Western SaharaNeutralnone
Iceland Flag
IcelandNeutralnone
Andorra Flag
AndorraNeutralnone
Greenland Flag
GreenlandNeutralnone
San Marino Flag
San MarinoNeutralnone
United States Flag
United StatesNeutral / Allies1917
Brazil Flag
BrazilNeutral / Allies1917
Philippines Flag
PhilippinesNeutral / Allies1917
Thailand Flag
ThailandNeutral / Allies1917
Italy Flag
ItalyNeutral / Allies1915
Belgium Flag
BelgiumNeutral / Allies1914
Portugal Flag
PortugalNeutral / Allies1916
Greece Flag
GreeceNeutral / Allies1917
Luxembourg Flag
LuxembourgNeutral / Allies1914
Tonga Flag
TongaNeutral / Allies1914
Colombia Flag
Colombianonenone
Sudan Flag
Sudannone1914
Peru Flag
Perunonenone
Chile Flag
Chilenonenone
Ecuador Flag
Ecuadornonenone
Bolivia Flag
Bolivianonenone
South Sudan Flag
South Sudannone1914
Dominican Republic Flag
Dominican Republicnone1916
Paraguay Flag
Paraguaynonenone
Uruguay Flag
Uruguaynonenone
Moldova Flag
Moldovanone1914
Albania Flag
Albanianone1914
Bahrain Flag
Bahrainnonenone
Guatemala Flag
Guatemalanone / Allies1918
Haiti Flag
Haitinone / Allies1918
Honduras Flag
Hondurasnone / Allies1918
Cuba Flag
Cubanone / Allies1917
Nicaragua Flag
Nicaraguanone / Allies1918
Costa Rica Flag
Costa Ricanone / Allies1918
Panama Flag
Panamanone / Allies1917
  • Data are based upon each country’s government and borders at the time of WWI, which may differ from their modern incarnations.
  • Participants that have dissolved since WWI, such as the Ottoman Empire, are typically listed under the names of the countries that currently exist in their place.
  • Participants that are not classified as sovereign states by the United Nations, such as the Andaman Islands, may not be listed.
  • Countries are placed into one of three categories based upon their level of involvement in WWI:
  • “Principal” countries were major participants in WWI
  • “Secondary” countries were slightly less impactful than principal combatants but still played important roles in WWI, such as providing supplies, sending large number of troops, or enduring military attack or occupation.
  • “Minor” countries played comparatively small roles in the war, but were still involved in some way, such as providing aid or sending small numbers of troops to serve in a primary participants army.
  • Many countries’ alignments shifted over the course of the war. For example, a country that was initially neutral may have been drawn into the fray by invasion from another country, and a country whose government allied with one side could switch allegiances after an internal coup replaced that government with new leadership.
  • Occupied countries present a unique case, as it could be argued they aided their occupiers’ efforts, although they did so grudgingly and without choice in the matter.
  • Perhaps surprisingly, sources disagree as to the date upon which WWI ended. Most commemorations mark the ending as 11 November, 1918, the date upon which the Armistice of Compiègne was signed, ending hostilities. However, some memorials maintain that WWI did not truly end until the signing of the Versaille Treaty on 28 June 1919.