USA HISTORY

Detailed explanation-1: -Europe’s leaders were willing to go to war to defend or extend national interests and their choices were shaped by a combination of long and short-term foreign policy goals, political pressures at home, previous crises, and the system of opposing alliances that had developed over the previous 35 years.

Detailed explanation-2: -After Austria-Hungary declared war on Serbia, Russia came to Serbia’s aid. This led to Germany joining the war to defend Austria-Hungary and then France and England joining to defend Russia. Due to the alliance system, a war between two nations turned into war throughout an entire continent.

Detailed explanation-3: -By 1914, Europe’s six major powers were split into two alliances that would form the warring sides in World War I. Britain, France, and Russia formed the Triple Entente, while Germany, Austria-Hungary, and Italy joined in the Triple Alliance.

Detailed explanation-4: -World War I had two main factions: the Central Powers, which included Germany, Austria-Hungary, Bulgaria and the Ottoman Empire; and the Allies, which included France, Great Britain, Russia, Italy, Japan and later, the United States.