WW2:
The Second World War resulted in an estimated 60 million displaced. That included roughly 12 million Germans, many of whom were forced to leave their homeland when large chunks of Germany's eastern borders were annexed to Poland. Many ethnic Germans were also expelled or chose to leave their homes in Eastern Europe.
Syria:
The continuing conflict and Islamic State offensive forced 1.5 million people to flee abroad in 2014, mainly to neighboring countries. The number of Syrian refugees now exceeds 4 million and another 7.6 million are internally displaced.
Korean war:
Estimates of the numbers of people displaced range widely, with anywhere from 1 million to more than 5 million forced to flee.
Iraq:
The Iraq War forced millions of Iraqis to flee their homes. At the end of 2014, there were almost 4 million refugees and internally displaced people.
Vietnam:
By the end of the two-decade conflict, more than 3 million people were estimated to have been displaced. Many were later resettled in the U.S. and China.
Rwanda:
The Rwanda 1994 genocide sparked a mass exodus of more than 2 million people from the country, according to the UNHCR. Another 1.5 million people were internally displaced.
Somalia:
Since the collapse of the regime of Siad Barre in 1991, Somalia has seen multiple waves of displacement over the years. At the end of 2014, it was the third-highest source of refugees in the world, with 1.1 million.
Israel-Arab war:
The foundational events of the Nakba took place during and shortly after the
1948 Palestine war, including 78% of
Mandatory Palestine being
declared as Israel, the
expulsion and flight of 700,000 Palestinians
https://graphics.wsj.com/migrant-crisis-a-history-of-displacement/
So why does Israel gets the special extra criticism?