Answer:
people invaded other countries and traded, spreading language and customs
So the Jews could be discriminated(bullied) and identified by the German people, them being identified was an important part of the Holocaust where it is said that nearly six million Jews were killed. Without the stars it would've been harder to identify them and perhaps less of them would have been exterminated(killed) by Adolf Hitler and the Nazi Party. Answer is Nuremberg Laws.
Domestic trends
There was an increased surge of nationalism in countries in Europe such as Spain under Franco, Italy under Mussolini and Germany under Hitler, which fueled dictatorial war ambitions. the financial conditions that hit the USA and European countries created conditions for hostility and conspiracies.
Foreign policy trends
increased imperialistic desires from European imperial powers and Japan increased tensions the weakness of the league of nation and the refusal of the usa to join it weakening it furtherthe formation of alliances also fueled tensionsthe policy of allied powers led by Neville chamberlain,called appeasement policy served to give the axis powers to prepare for war.
