World War II was the greatest conflict in human history and it laid the foundation for the current global order that we see today. One of its first effects was the decline of colonial powers like France and the UK. At the same time, it led to the emergence of two distinct power centers, the US and the USSR. These post WW2 developments are discussed in detail below:

1.  Collapse of economies: At the end of the war, most European economies were in tatters and their industrial infrastructure had been obliterated. This was true in particular for France and the UK as they were early entrants in the war unlike the US. They had to rely on the Lend-Lease aid provided by the US during the war and the Marshall Plan after the war to prop up their economies.
2.  Emergence of new superpowers: The US and the USSR emerged as the two new superpowers after the war. Their massive industrial capacity and huge populations helped them attain this position. France and the UK could no longer unilaterally call the shots at the world stage.
3. Decolonisation: The Allied war effort’s core beliefs of freedom and self-determination challenged the legitimacy of colonial control. Faced with a number of issues domestically, they could no longer hold on to their colonies in Asia and Africa and thus ended up losing their spheres of influence.
4.  Creation of New International Structures: The Bretton Woods conference during WW2 led to the formation of a new economic order. Another organisation formed after WW2 is the United Nations. Both these systems were created under the leadership of the US which shows the change in global power dynamics.

It is irrefutable that WW2 reduced the importance of France and the UK at the world stage. Economic devastation, decolonisation and emergence of new superpowers all led to this shift in the global order and its effects are still seen today.