Question

what area was known as Balkan and why these areas are called the area of tension

Answer 1

Few issues in modern history have received as much attention as assigning blame for the outbreak of the World War in 1914.  The debate began during the war itself as each side tried to lay blame on the other, became part of the "war guilt" question after 1918, went through a phase of revisionism in the 1920s, and was revived in the 1960s thanks to the work of Fritz Fischer.