How Involved Were Countries?Of course, these levels of 'involvement' differed hugely. Some countries mobilized millions of troops and fought hard for over four years, some were used as reservoirs of goods and manpower by their colonial rulers, while others simply declared war late on and contributed only moral support. Many were drawn in by colonial links: when Britain, France and Germany declared war they were also committing their empires, automatically involving most of Africa, India and Australasia, while the entry of the US in 1917 prompted much of central America to follow.
Consequently, the countries in the following lists did not necessarily send troops and few saw fighting on their own soil; rather, they are countries who either declared war or were considered involved in the conflict (such as being invaded before they could declare anything!) It's important to remember though, that the effects of World War 1 went beyond even this truly global list: even countries who remained neutral felt the economic and political effects of a conflict which shattered the established global order.
Countries listed by continent
Countries listed alphabetically
Countries in the British Empire
Countries in the French Empire
Countries in the German Empire
Map of the Globe showing relevant countries
Did You Know?:• Brazil was the only independent South American country to declare war; they joined the Entente countries against Germany and Austria-Hungary in 1917. Other South American nations severed their relations with Germany but did not declare war: Bolivia, Ecuador, Peru, Uruguay (all in 1917).
• Despite Africa's size, the only regions to remain neutral were Ethiopia and the four small Spanish colonies of Rio de Oro (Spanish Sahara), Rio Muni, Ifni and Spanish Morocco.