Why did Germany declare war on France in World War 1?

Answer 1

After Germany declared war on Russia to help Austria-Hungary (who was attacked by Russia after they attacked Serbia), France made clear their intent to stand by their ally (Russia, obviously), so Germany declared war on them, too, planning to take them out then go after Russia to prevent a two-front war. Unluckily for Germany, Russia prepared pretty quickly so Germany had to send troops to the Eastern Front as well and fight a two-front war.

Answer 2

Germany declared war on France because France was allied with Russia.

The sequence goes like this, in short:

Austria, Germany and Italy were allied.

Russia, England and France were allied.

England had a side treaty with Belgium, saying they would defend Belgium.

Russia had a side alliance with Serbia.

The heir to the Austrian Imperial throne was murdered. Austria believed some Serbians helped (Serbia and Austria didn't like each other). Austria demanded a list of things from Serbia; Serbia agreed to all but one. Austria declared war on Serbia.

Russia then declared war on Austria because they were allied with Serbia.

Germany declared war on Russia because they were allied with Austria. They knew France was going to join in because of their alliance to Russia, so Germany declared war on them too.

England waited a few days, and technically didn't declare war until Germany invaded Belgium- Germany's plans to defeat France involved taking a shortcut through Belgium, without Belgium's permission.

Another interesting note is Italy. Because Austria declared war on Serbia, Italy said that they did not have to join the war since Austria was technically the attacker. They eventually joined the Allies (Italy had historically disliked Austria, and never really wanted to be allied with them).

Answer 3

Prussian was viewed as the leading Germany power after their victory in the Austro-Prussian War and Napoleon III, emperor of France, did not like that too much. It was also provoke by Otto von Bismarck, chancellor of Prussia, in an attempt to make Germany a nation union.

Answer 4

Britain and France had a defence agreement with Poland. On 1 September 1939, German troops attacked Poland, so on 3 September 1939, Britain and France declared war on Germany.