"If we do not end war - war will end us. Everybody says that, millions of people believe it, and nobody does anything." - H.G. Wells
Drastic changes of World: Social - Economic - Political
     Eric Hobsbawn, a historian, called the 20th century "The Age of Extremes". So many social, economic and political changes were happened during the 20th century. The world had a population of 1.6 billion people at the beginning of the 20th century. Literary levels and average life expectancy grew immensely for all. New forms of art like movies emerged.
    Industrial capitalism changed the world countries in many ways. Some of these countries, especially Britain, were leading Industrial powers and also held vast colonial empires, spread all over the world. The world was divided into 'the West", which was experiencing economic growth and the 'the Rest', whose acute backwardness was worsened by colonial exploitation by the West. Industrial capitalism had changed the way of earning in western countries.
   Politically, the world saw shoots of democratic aspirations grow amidst the rise of Fascist domination which fostered ideologies of unquestioned power and hatred for other people. Literally more than a hundred nations walked to independence and freedom across the world. Women got their right to vote in this period, starting with the west.
     This was also an age of great experimentation as people strove to build socialist societies based on the principles of equality and fraternity or alternatively a liberal democracy based on political liberty and capitalist economy. But the same period saw the "Great Depression" causing massive unemployment and economic breakdown and two World Wars in which millions died and the lives of many more millions were dislocated.
   Science knowledge rose to new heights unlocking the secrets of atom and life. Hence, the 20th century was a period of great expectations, experiments and dangerous developments.

World Wars: Ominous Facts
     At the beginning of the century, the world was divided into Developed Industrial Countries of the West (including USA, Germany, France, Italy, Japan etc.,) and Colonial countries of Asia and Africa. While the colonial countries were just beginning their struggle for independence the industrialised countries were at loggerheads with each other. They were divided into rival blocks (Germany - Austria - Hungary Vs Britain - France - Russia), each vying for world domination which would give it control over the colonies and markets.
The First World War broke out in 1914. It was truly a World War as virtually no country was left untouched by it in the world. It ended in the defeat of Germany and its allies and in the victory of Britain and France in 1918. The Peace Treaty between them, which created the seeds of another and more deadly war from 1939 to 1945. This war too was fought between Germans and its allies on the one side and Britain, France, China, USSR and USA on the other side. It ended in the defeat of Germany and its ravaged all the warring countries.

Death and Destruction
    The two World Wars were different from other wars the world had been till then. The death and destruction caused by them was imprecedented. The wars resulted in an enormous loss of men and material. The estimated loss of life on all front wars, nearly 1 crore people in first World War and about 2.2 to 2.5 crore people in the Second World War. The US attack on Hiroshima and Nagasaki in Japan with atom bombs which killed between 1,50,000 to 2,46,000 people immediately. The after-effects of these bombings like leukemia and cancer lingered on for decades.
    The precious wars between Nations may have lasted longer but those wars were not geographically as widespread nor their effects as lethal as the ones in the 20th century.

Power Blocs
     A number of European countries entered into secret alliances to safeguard their freedom and the commercial and economic interests. Germany formed the dual alliance with Austria - Hungary in 1879. Italy joined them. The treaty was changed into 'triple alliance' in 1882. England joined Russia and France and thus formed triple entente.
     Similar blocks continued into the Second World War the Axis powers led by Germans and the Allies led by Britain, US and USSR.

Causes of the Two World Wars Comparison
    The causes for World Wars are to be found in several historical developments which took place in Europe since few decades before the actual outbreak of the wars. The two World Wars of the 20th century were also dissimilar separated as they were by 21 years and changes in economic conditions, diplomatic alliances, military hardware etc., However, for purposes of understanding the differences, comparing the two World Wars of the 20th century will be a good method.
    Aggressive Nationalism, Imperialism, Secret Alliances and Militarism were the main long term factors which led to World War - I. These causes continued to push the world to war but some new long term causes were also added to the origins of World War - II. One of them was the dissatisfaction of Germans with the legacy of World War - I. First, we will compare the immediate provocations and then, the main causes of these two World Wars.

(A) Immediate causes
    Every war is triggered by some immediate provocations built upon some longterm causes. The immediate provocation for World War - I was the murder of Ferdinand the crown prince of Austria along with his wife Sophia by a Serb in Sarajevo on 28th June 1914. Then Austria declared war on Serbia. As Serbia was with allied powers (like UK, France, Russia) the Austrian attack on it led these powers to came to Serbia's defence. Then the central powers (like Germany and Italy), allied to Austria, also joined the War and this marked the beginning of the First World War.
     Hitler's attack on Poland was the immediate provocation for the Second World War. Peace conference of Paris made Poland an independent state. In order to open her to the Seacoast a way was made running upto the Danzing port. Germany was thus torn into two parts. When Hitler came to power, he demanded the annexation of Danzing to Germany, on the ground that it was habituated by the Germans. He also demanded the closure of Polish corridor. Poland refused to accept the demands of Hitler on the strength of French support. On this refusal, Hitler attacked Poland on 1st September, 1939. For this move France and England declared war on Hitler. Thus the Second World War began.

B) Aggressive Nationalism
    Newly independent countries like Germany and Italy had changed the balance of power in Europe. They had won freedom on account of intensive nationalism among their people, who had grown proud of their race. The relation between Germany and England worsened owing to racial - feeling. Aggressive nationalism created troubled spots in Africa, Asia and particularly in the Balkans.
    The harsh terms imposed by the treaty of Versailles had led to the growth of strong and aggressive nationalism in those countries. The dictators like Hitler and Mussolini have roused the racial feelings. They advocated to their people about the superiority of their races. Mussolini of Italy, Hitler of Germany, Stalin of Russia and Franco of Spain had risked their nations towards attainment of supremacy in the world. Japan started the slogan Asia for Asiatics.
          
C) Imperialism
     "Second World War was the intensified struggle for power between the have and have not nations" -Prof. Ferdinand Schevill
     An industrial capital developed in the European countries like Britain, Germany and US, they needed markets for their products and access to raw materials. As capital further accumulated in banks and financial institutions, they looked for safe investment opportunities in colonies. Thus by the end of the 19th century there was a race for colonies between the European powers. The governments of these countries acted on behalf of their capitalists to increase their areas of influence and reduce the areas under their competitors. As new industrial powers (like Japan, Germany and Italy) emerged they wanted to redivide the colonies but the old powers were not ready for this. This created much stress often leading to wars.

(D) Secret Alliances
"Systems of Alliances was the curse of modern times..." -Prof. Fay
      After defeating France in 1870, Bismark, the German chancellor, decided to isolate it. To achieve this end, he entered into a secret alliance with Austria in 1879 and with Italy in 1882. This defensive alliance was meant to partly save Austria from Russia and Italy from France. The special context of the second World War  In addition to above cause, the following causes were responsible for outbreak of the Second World War.

(a) Humiliating Terms of the Treaty of Versailles
     The allies of the First World War had happened a lot of humiliation on Germany by the terms of the Treaty of Versailles. Germany was shorn of all her past glory and possession. Germany was deprived of her territories in France. She was cut into two parts by establishing a polish corridor. Her navy was completely destroyed. Army was reduced to an insignificant size. She was deprived of her coal and steel resources. She was to pay reparations which were beyond her capacity to pay. Germany was to be occupied by the foreign troops to enforce the provisions of the treaty. She was crippled both economically and militarily.

(b) Failure of the League of Nations
    The Treaty of Versailles also set-up the League of Nations to prevent wars in the future. The big powers Russia, USA, Germany were not joined as members of the League of Nations. It also set up several international agencies for conducting welfare activities like health, labour welfare and also an International court of Justice for legal disputes between nations. Eventhough it showed a lot of promise and much was expected of it, it failed eventually to prevent Germany and Italy from violating International agreements and attacking other countries.

(c) German Challenge to vengeful domination
     After the defeat of Germany at the end of the first World War in 1919, the Victorious Allies wanted to punish Germany for starting the war and also cripple it so that it cannot rise again. For the Germans, the provisions enforced on them by the treaty of Versailles were Slavish. This created a reaction in Germany which led to the rise of Hitler and his Nazi party. They wanted to recover the territories lost by them in the Treaty of Versailles, restore Germany dominance over Central Europe and end the restrictions on German armaments. Germany industrialised itself furiously under the Nazis and developed a massive army and armament industry which could only be served by a war.

(d) The Fear of socialism and the USSR (or) Ideological conflicts
     After the first World War, there arose an ideological conflict among democratic and dictatorial nations. Democratic countries namely England, France and America treated Italy, Germany and Russia as their enemies. Italy, Germany and Russia treated France, England and USA as their enemies. Russia treated Fascists as its enemies. The Fascists of Germany and Italy tried to take precautionary measures to check that the people of other nations do not get influenced by the communist ideas.
In 1936, Japan, Germany and Italy signed the Anti - commintern pact.
Consequences of World Wars
     The World Wars had a long lasting impact on the politics, society and economy of the world. These can be enumerated as follows:
(a) Political Consequences:  The Wars ended Britain's leadership of the world. It was now taken over by America and Russia. European Supremacy over Asia was lost. Several countries including Burma, Ceylon, Egypt and Malaya were granted freedom after the war, with the withdrawal of British sovereignty over them. France, Portugal and Holland also lost their rich colonies in Asia. The armed supremacy of America and Russia again brought the world to be divided into two opposite power blocs, one dominated by capitalist America and the other by the Communist Russia.

(b) Economic Consequences
     The wars resulted in an enormous loss of men and material. The loss cannot be estimated exactly even by the experts in mathematics, economics and by statisticians. For example in World War - II, Britain alone spent about two thousand crores. Russia had drained one fourth of her entire national wealth. The loss occurred in Poland, France and Germany could not be computed.

(c) Democratic Principles asserted
    The two wars also brought home the dangers of having undemocratic governments and greatly strengthened the case for democratisation of power. Several empires were ended. Countries like Russia saw a socialist revolution while others like Germany became a Weimar Republic. Turkey turned as a democratic and secular state. With the process of decolonisation, after World War - II, the colonies rose to independence and accepted the principle of democratic rule. 

(d) New International Organisations
      After World War - I, the League of Nations was formed to resolve disputes peacefully but it was failed. The United Nations Organisation (UNO) was formed after World War - II. UN is a kind of world government based on four principles, viz. preserve peace, uphold human rights, respect International law and promote social progress. It works through organs like UNICEF, UNESCO, WHO, ILO etc., The UNO despite being accused of becoming a tool of the great powers like USA and USSR has managed to prevent wars on the scale of the Second World War.

(e) Enfranchisement of Women
      After a long struggle for political right to vote - British Women got these rights in 1918. In the long protracted wars like the World Wars, industrial production and other services are necessary. With men away in the battle fields, more women had to work in factories, shops, offices, voluntary services, hospitals and schools. Beginning with the confidence of being bread-winners, women began raising their voice for equality in all walks of life. Getting the right to vote was a big step in that direction.

Main Points

* During 20th Century, there were so many political, social, economic changes occurred. The population rate, the literacy levels and the life expectancy were increased.
* Industrial Capitalism divided the world into the Developed and the Backward countries. Also the great depression in 1929 caused for more economic problems.
* Fascist Political Systems were grown.
* The 20th Century was a period of great expectations, experiments and dangerous developments like use of nuclear explosions.
* Colonial countries of Asia and Africa were exploited by the industrial developed countries of the west.
* The most important incidents in 20th century was the out break of Two World Wars in 1914 - 18 and 1939 - 45.
* The European countries formed the Secret Alliances for their self-interest. Germany, Italy and Austria - Hungary formed Triple Alliance and England, Russia, France as Triple Entente at the time of World War - I. These groups continued into the Second World War as the Axis Powers and The Allies.
* The immediate provocation for World War - I was the murder of Ferdinand, Austrian Prince on 28th June 1914 and for the Second World War was Hitler's attack on Poland on 1st September 1939.
* Aggressive Nationalism, Imperialism, Secret Alliances and Militarism etc., were the main causes for the outbreak of Two World Wars.
* Aggressive Nationalism is the feeling of people of one country proud of race wanted to establish their supremacy over the World.
* Imperialism is a form of exploitation of one nation by another the rivalry in colonial expansion was called Imperialism.
* The World War was different in many respects from the World War - I. It was a total war in which all resources of the states involved were mobilised.
* The humiliation meted out to Germany by the treaty of Versailles caused resentment to its people. So they were waiting to take revenge. Hitler took advantage of this feeling among people and aroused the racial feelings of Germans through his speeches.
* Germany was determined to assess her position as a World Power. This behaviour of Germany was very much responsible for the World War - I.
* An ideological conflict among democratic and dictatorial nations arose after the World War - I. There was a quarrel between socialist and facisit countries.
* The two World Wars changed the world in social, economic and political fields. The loss of men and material were enormous.

* League of Nations owing to its own limitations could not succeed in checking the aggressive designs of several countries and it miserably failed to restrict the race for arms. It remained as a spectator to the developments.
* The wars changed the political scene of world. Most of the Asia and African colonial countries granted freedom. European supremacy was ended. The world divided into USA's power bloc and USSR's power bloc.
* The newly independent countries and other countries were termed as democratic states.
* The Women also fought for equality and got 'Right to Vote'.
* Also setup UNO to prevent future wars and promote peace and security. Its main organs are UNESCO, WHO, UNICEF, ILO,... etc.