Who were the 5 important people involved WW1?

Answer 1

What you are asking for is essentially insane. Who were the five most important presidents? What were the five most important gods in history? Who were the five most vicious killers of all time? Any answer is totally subjective and cuts out any of the meaningful social, economic, political, religious or personal connections of anyone involved by boiling it down to some base creature which completely fails to give any feeling of such a massive and overwhelming thing that is human history.

That said...

Prince Otto Von Bismarck: For creating the international order which allowed for the entire political scene to unfold.

Fredrick Wilhelm II: For pursuing aggressively nationalist foreign policy along with military build-up which threatened the status quo.

Czar Nicolas II-Failure to reform and maintain Imperial Russia led to inability to effectively counter the Germans or Austro-Hungarian Empire which greatly inhibited the Allies through 1917 and ultimately led to the collapse of the Empire and their withdrawal from the war.

Woodrow Wilson-For bringing the US into the war which decisively ended the war in the Allies (and American) favor instead of a slow grinding defeat for England and France.

Vladimir Illyich Lenin- For signing the Treaty of Brest-Litovsk and granting the Germans enormous reprieve to continue the fighting.

I choose these people because they had enormous and long lasting influence on the conflict as well as enormous personal presence to those who were experiencing history.

Answer 2

It is estimated that WW1 cost the lives of 9.7 million military personnel and 6.8 million civilians.

So which 5 were you after?