The first world war and the second world war remained to be the total war. In other words, we can say unlike earlier wars in these wars particularly there was a wide extent of participation of the civilian population apart from the army. In fact, the role of civilians became as much prominent as that of an army in the sense that it is through the economic strength that a nation could sustain such a long stretched war.
In course of these wars, the human massacre became a general feature. For example- in course of the first world war the Ottoman empire committed mass killing in Romania. Likewise earlier than the second world war and even in course of it, Hitler eliminated almost 60 lakh Jews and Gypsies. Above all the mass killing committed in course of two world wars was different in nature from earlier killings because the mass killing was done under the supervision of the state and with the help of the latest technology in form of a Gas Chamber etc.
In the course of the world wars machinery for the destruction of humankind were developed. For example- it was in the course of the first world war that chemical weapons developed. Likewise in course of the second world war, Nuclear weapons came into existence.
The question of refugees became an important issue between the two world wars. Under fear, the migration of population from one region to another became a general phenomenon. For example- as a result of the persecution by the Nazi party Jews started to migrate to the Philistine region.
In one sense world wars encouraged the process of democratisation. For example- after the first world war the three important dynasties in Europe Hohenzollern dynasty in Germany, the Romanow dynasty in Russia and Habsburg dynasty in Austria declined. Furthermore, the nationalist movement started in nations like Greece and Egypt. Likewise, after the second world war, there was a decline of Fascist power in the world.
In course of the first world war as the result of the larger involvement of the male members on the battlefield, women were encouraged to take participation in production. So the natural result was the wider participation of women in the economic and social life of Europe. Consequently, the participation of women increased even in political life. So after the first world war empowerment of women became a general phenomenon in European life. It was during this period that the feminist movement started. Likewise, after the first world war, franchisement was extended among industrial workers as well.
One consequence result of the first world war was the world economic depression. As a result of this, there was a total disruption in world economic activities. In one sense it created a stronger psychological impact even than the first world war because the people were quite unable to find out the cause behind this economic crisis. In fact, it was impersonal in nature. So it was not man-made according to the people.
In course of the two world wars Europeans started to think in terms of an international organisation because according to them it was selfish nationalism that resulted into world wars. So after the first world war the league of Nations was formed. Likewise after the second world war U.N.O. came into existence.