Young European men overwhelmingly do not support immigration of muslim and African men. The problem is that women are allowed to vote and older men, who are too old to care or already reproduced or don't care enough anymore, because too old. Young men are always a minority of voters. World War One ruined Europe forever, it resulted in income taxes, welfare states, women working outside homes, voting rights for women... WW2 was a direct part two that introduced human rights, the rights to asylum (that you guys abuse/misuse), ending of eugenics policies, loss of colonies, development aid was invented post WW2. Without money, technical help, capacity building etc. from Western Europe, Japan, Australia and the USA and Canada, literally billions of people would not exist now/would die. We fund our enemies (who hate us, but still demand more aid from us in all UN conferences and treaties) who procreate like rabbits at our expense. We send our warships to protect food aid deliveries to Somalia, where the carrying capacity of the land has been exceeded long ago. We fund the population explosion in Afghanistan even after Taleban took power and the land can't support even the current population, not to mention the future population projections. EU had meetings with Taleban and confirmed to Taleban that the EU will not allow famine in Afghanistan and will continue some development projects while not demanding to bring down the super high total fertility rate.
BTW, Iraq had 3 million people only a century ago, which is not a long time. Now it has 42 million people.