BERLIN — When thousands of refugees arrived at the main train station in Munich last weekend, hundreds of awaiting Germans held up signs saying "Welcome Refugees." Many of the travelers, though tired and exhausted from their dangerous and long journey, expressed joy and thankfulness. Watching those scenes, viewers around the world got the impression that something exceptional was happening: Germany was welcoming strangers who didn't seem welcomed anywhere else.

The enthusiasm will be remembered -- but will it last? Germans seem to be enjoying that the nation is finally making positive headlines after months of arson attacks on refugee centers and anti-foreigner protests.

Although the protests are supported by only a minority, they have not gone away. Chancellor Angela Merkel might not want to admit it, but assimilating and caring for up to 500,000 new refugees every year will probably cost more than the $6 billion she expects, Germany's state governments warn. Will Germans still welcome refugees if their taxes have to be raised as a consequence? And how will they react to those who don't learn the German language or otherwise fail to assimilate?

Germany is about to face its biggest challenge since reunification.

When the German government closed its border to Austria on Sunday and reinstated controls and identity checks, some who oppose the influx felt vindicated. Germany's interior minister, Thomas de Maiziere, said on Sunday that the measures had been taken for security reasons. However, he added that the move was also a warning to other E.U. countries to take in more refugees.

In taking those steps, Merkel is trying to balance the interests of her coalition partner, the Christian Social Union (CSU), which tends to be less supportive of accommodating refugees than the Social Democrats. The CSU, which is based in Bavaria close to the Austrian border, had sharply criticized the chancellor for her decision to allow tens of thousands of Syrians to cross the border in recent days.

Timo Lochocki, a fellow at the German Marshall Fund, a transatlantic think tank, expects that Merkel and her coalition government will be able to preserve the public's positive feelings about the influx at least until next spring. "Many Germans have enormous trust in the current government because they think it has mastered the Greek crisis perfectly," Lochocki said. Germany's tough stance toward Greece earned the country a reputation abroad as a  brutal enforcer of financial discipline. But that benefited Merkel at home. "After having been tough on Greece, she can now pursue an open arms policy for refugees."

Germany's "welcoming culture" is a widespread societal phenomenon

Although there are many more projects in the west of Germany than in the east, the per capita ratio is nearly the same. Of Germany's 81 million inhabitants, only about 16 million live in eastern Germany, which explains the smaller number of projects.

There is at least one bigger volunteering project for every 180,000 people in the west, that number stands at 200,000 in the east -- including Berlin. In many cities, authorities have urged the public to stop making donations to refugee shelters: There simply has been too much support.

What will happen if the enthusiasm fades?

However, assimilating refugees necessitates much more than a temporary enthusiasm: If Germany really wants to fill its demographic gap by attracting young refugees, it will have to provide them with proper education, job prospects and monthly

payments. Many young asylum seekers won't become working-age adults for years. In the meantime, Germans will have to carry the financial burden -- even if its currently strong economy eventually weakens.

Already today, 12.5 million Germans live in poverty, according to a report by Germany's Joint Welfare Association Paritätischer Wohlfahrtsverband. It's the highest number in the history of reunified Germany.

As WorldViews explained earlier, 60 percent of Germany's unemployed do not fall below the poverty threshold, whereas about 3 million employed do. The number of people who are poor despite having a job has increased by 25 percent from 2008 until 2013. In other words: For some, it is financially more beneficial to be unemployed in Germany than to have a job.

Germany's wide gap between rich and poor might partially explain why millions of Germans are not quite as welcoming to asylum seekers as recent images have suggested.

The dark Germany, explained in maps

Recent data, visualized by The Washington Post, show the trend: In western German states, there seems to be a correlation between arson attacks on asylum centers and the number of refugees sent to those regions.

Refugees are not free to choose where they will be accommodated. Instead, German authorities determined how many refugees each federal state has to accept. A state's GDP and size are among the factors which determine that number. The richer and more populated a state is, the more refugees it has to accept. What appears frightening is that arson attacks have occurred even in the more culturally diverse, relatively wealthy and most populous states: North Rhine Westphalia and Bavaria.

The German government has said it is open to accepting up to 500,000 annually in the coming years. If arson attacks increased proportionally, it would likely become necessary to protect asylum centers with police patrols -- raising the costs of accommodating asylum seekers even further.

In July, Der Spiegel  asked in a cover story: "This year, about 400,000 refugees will come to Germany, which will cause a painful debate: Will our welcoming culture resist?" Shortly after the article was published, the German government raised its predictions: Now, it expects 800,000 refugees to arrive by the end of this year.

Eastern Germany would be particularly prone to escalation

The country's east is dealing with an even more explicit anti-foreigner sentiment: Saxony, the richest and most populated state in the east, is also the nation's most dangerous place for refugees. Tensions are also running high in neighboring states: Most reported attacks and other acts of violence have originated in the east, despite the fact that only about one-fifth of the country's total population lives there.

Eastern German right-wing extremists have attacked the refugees themselves, rather than their housing centers. Such aggression builds on criminal neo-Nazi structures, which some experts would call right-wing terrorism.

Germany is still dealing with the fallout from the National Socialist Underground (NSU), an anti-Muslim terror group based in the east that killed 10 people – most of them Turks – between 2000 and 2007. Back then, investigators blamed Germany's immigrant community for most of the deaths and portrayed them as the result of infighting and organized gang crime.

Eastern German authorities have struggled for years to cope with the large number of attacks on foreigners. But why is there so much aggression toward newcomers in the east?

Some would say it is just that: There aren't many foreigners in eastern Germany, as this map shows.

In the state of Saxony, only 2.5 percent of inhabitants do not have German citizenship. In many western German regions, the ratio is about 10 percent.

"Many eastern Germans know only few or no foreigners; they are scared because they have no idea what to expect from the influx of refugees," political scientist Werner Patzelt explained earlier. The rise in violent xenophobic crimes will make it even more difficult for those afraid of more immigration to make positive experiences with foreigners. Their fear won't go away anytime soon.

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