The correct answer is - 1. WW I, WW II, Cold War, Creation of European Union.
The WW I started in 1914, the WW II started in 1939, the Cold War started in 1947, and finally the European Union was formed in 1950.
This events are all connected to each other and emerged as a result of the previous one. The WW I contributed to rise in nationalism in Europe and forming of alliances with different interests and all with a goal to enlarge their territories and become the dominant force, that led to the WW II. The outcome of the WW II led to big competition between the USA and USSR on a global level to try and become the dominant world power, which led to the Cold War that lasted for half a century and divided the world economically and politically. The battle between the USA and USSR made the European countries to come to peace with each other and in attempt to become an economic power they united as an economic union which marked the beginning of the European Union.
