A good starting point is to list all of the nations that were represented at the peace conference in 1919.
These were 32 allied and associated powers, either as voting members or as observers. This number consisted of:
- The thirty sovereign nations that declared war (see list to follow),
- Less Montenegro, which was included in the 1919 Jugo-Slav state along with Bosnia, Croatia and Slovenia,
- Less Newfoundland and
- Including Czechoslovakia, the Arab state of Hedja, Poland and the 1919 Jugo-Slav state.
The five defeated nations were also allowed to be represented but were excluded from all of the deliberations.
Allies that declared war and engaged in military action: 20 – Australia, Belgium, Brazil, Canada, France, Greece, India, Italy, Japan, Montenegro, Newfoundland, New Zealand, Portugal, Romania, Russia, Serbia, Siam, South Africa, United Kingdom and United States.
Allies that declared war but didn’t engage: 10 – China, Costa Rica, Cuba, Guatemala, Haiti, Honduras, Liberia, Nicaragua, Panama and San Marino.
Allies who broke diplomatic relations with Germany but didn’t declare war: 4 – Bolivia, Ecuador, Peru and Uruguay
Total of the above: 34
Modern nations that were part of combatant allied empires or nations in 1914 and were actively involved in the war in some way:
American ‘Empire’: 1 Philippines
Belgian Empire: 1 Congo
British Empire: 19 Ireland, Bahamas, Belize, Bermuda, Jamaica, Barbados, Zambia, Malawi, Uganda, Kenya, Ghana, Zimbabwe, Egypt, Nepal, Myanmar, Pakistan, Sri Lanka, Bangladesh, Singapore
French Empire: 10 Malagasy, Senegal, Mali, Mauretania, Algeria, Morocco, Tunisia, Cambodia, Laos, Vietnam
Japanese Empire: 3 Korea (2), Taiwan
Portuguese Empire: 2 Angola, Mozambique
Russian Empire: 16 Poland, Belarus, Ukraine, Moldova, Lithuania, Latvia, Estonia, Finland, Armenia, Georgia, Azerbaijan, Kazakhstan, Tajikistan, Uzbekistan, Kyrgyzstan, Turkmenistan
Serbia: 2 Macedonia, Kosovo
Total for this group: 54
Central Powers that declared war:
Austria-Hungary (2), Bulgaria, Germany and Ottoman Empire.
Total for this group: 5
Modern nations that were part of combatant Central Power empires in 1914 and were actively involved in the war in some way:
German Empire: 11 – Namibia, Tanzania, Rwanda, Burundi, Papua New Guinea, Marshall Islands, Palau, Kiribati, Samoa, Togo, Cameroon
Austro-Hungarian Empire: 5 – Slovenia, Czech R., Slovakia, Croatia, Bosnia
Ottoman Empire: 12 – Syria, Palestine, Israel, Jordan, Iraq, Saudi Arabia, Yemen, Oman, Qatar, UAE, Kuwait, Bahrain
Total for this group: 28
Countries that didn’t declare war but were nevertheless actively involved in some way: Albania, Chile, Luxembourg, Mexico, Persia, Vatican
Total for this group: 6
Grand Total 127
76 countries sent participants to the 2014 Bastille Day Parade in Paris that also recognized the centennial of the First World War.