Answer:
To protect their freedoms and property.
The Ancient Persians invented their own alphabet, the wind-power machine and Qantas, a water irrigation system. They also developed their own coinage system.The ancient Persian leaders worked hard to ensure their empire succeeded.
The Persian Empire was important for many reasons. ... The Persians developed their empire in a manner that future empires would emulate. The Persians created a mail system. They built roads and developed a communication system throughout their empire.
The Serbian Expansion and Russian role in the Balkans.
Combined with the increase in Russian military strength, both Austria and Germany felt threatened by Serbian expansion; when Austria invaded Serbia on 28 July 1914, Russian Foreign Minister Sergey Sazonov viewed it as an Austro-German conspiracy to end Russian influence in the Balkans.
On 30 July, Russia declared general mobilization in support of Serbia; on 1 August, Germany declared war on Russia, followed by Austria-Hungary on 6th.
