Mass migration has caused many problems across Europe in many different forms by different groups, but more perceived losses than gains from the poorer in 1st world country's society due to globalization, rising crime and the 0.1% who engage in terrorism which has lead to almost 500 deaths in the last year and the main political parties not wanting to engage with and discuss peoples genuine grievances, especially the left, so they are turning to the hard-left and right parties with their simplistic populist policies and solutions. Our current major disruption political era will end like the last one unless lessons are learned and there are more political openness and POLITE constructive discussion between the parties and the people. IMO it is inevitable, unless things change fast, that we will end up like the last major disruptive political era of the 1920's and 30's which we will again end in a major war except this time with nukes.
I have been called several times a Nazi, racist and eugenist by a left-wing person on here who objected to some of the issues I have raised where they don't think they should be discussed. Bipartisan politics in the US especially with the left's normal sanctimonious we are always correct, you thick, racist, deplorable has resulted in the white supremacist mafia criminal buffoon Trump being elected which is doing much damage to the USA's cohesiveness, credibility and international status than ever before.
I see Merkel like Cameron is saying lessons will be learned from the election, which is for any elected parties basically telling the electorate to go forth and multiply.
With Obama/Kerry deeply flawed Iran nuclear deal meaning that they will legally have nukes in about 8 years and will almost certainly use them against Israel, Europe and the US once they have. I'm really not hopeful that most of humanity will make it much beyond 2025-2030.
The situation in the 1920's, 30's was vastly different than now, especially in Germany. That is why, strangely for me, I am down playing any potential repeat of history.
In 1919 Germany suffered the humiliation of the Versailles Treaty coupled with the wide spread belief they had not actually lost the Great War but following the Armistice had watched what Hitler called the Gang of Criminals sign away their countries respect, pride and honour, worse still suffering this all with their long term enemies, France, gloating. Then there was severe political unrest in Germany, with the Economic Depression coming on in 1929, causing hypo-inflation and mass unemployment. Hitler rose like a shining light to be seen by many to be a messiah, with his promises of a great future for the Fatherland if they shared his vision of an enlarged Germany, fit for natural Aryans and no others, with a restored military to bring back national pride and defend themselves against the evil of those nations who condemned them to such humiliation in the form of the Versailles Treaty, and who allowed France, with Belgium, to take control of the Rhineland in 1923 until 1925. He, then the Third Reich, wanted revenge. He saw foreigners as the cause of Germany's woes, and especially the Jews and Communists who were going to be made to pay for their "crimes".
So none of this history can be related to the current situation in Germany.
The main worry for us all is much further East. The question of North Korea which could well result in some form of major conflict.