Thilo Sarrazin, a politician and outgoing executive of Germany’s national bank, has ignited fierce debates over Europe’s “Muslim problem.”

A few weeks ago he published Deutschland schafft sich ab (“Germany is eliminating itself”), a 450-page manifesto on the failure of the country’s integration policies.

Sarrazin says his country’s Muslims refuse to integrate and are soaking up generous welfare reserves. He cites his country’s declining birth rate and notes how Muslim families with very little education are having what he considers too many kids, thus making Germany a poor and stupid nation. A passage from the book, translated by The Economist: “With higher relative fertility among the less intelligent, the average intelligence of the population declines.”

This isn’t the first time Sarrazin has made headlines. Last year, he said many Muslims in his country had the intellectual capability of fruit vendors and opined that “I do not have to acknowledge anyone who lives by welfare, denies the legitimacy of the very state that provides that welfare, refuses to care for the education of his children and constantly produces new little headscarf-clad girls.”

In his latest book, he advocates changing welfare policies to boost fertility among smarter families. In a country where the Holocaust was engineered, the promotion of eugenics is profoundly disturbing. High-profile political and media figures have denounced the book and the mainstream socialist party in Germany is considering revoking Sarrazin’s membership.

But the book sold out within a few days. German pollster Forsa found that half the population supported his views and a fifth would vote for a party if Sarrazin created one.

Sarrazin’s book has revealed two things. First, European political parties have been urging political correctness to the point of alienating the public’s frustrations. More importantly, assimilation has failed.

Like all of Western Europe, Germany has a significant and growing Muslim population, largely immigrant families from Turkey, Morocco, and Egypt. Similar to ghettoization in France, many live in low-cost suburban apartment buildings were unemployment and violent crime is high. Illiteracy is commonplace, as is a lack of fluency in the country’s language.

Meanwhile, European voters are continuously told to shut up over racial issues. Mainstream parties promote diversity while ignoring public frustration. A telling example occurred in the UK election this spring, when then-prime minister Gordon Brown famously called a woman a “bigot” for complaining about EU nationals from Eastern Europe taking all the jobs in her city.

Only far-right nationalist groups are responding to widespread anger by proposing radical, inhumane solutions such as mass deportations, reverse-affirmative action, and internment camps.

And they’re gaining support. Last year, Geert Wilders, a Dutch politician known for his anti-immigrant views and his documentary linking the Qur’an to extremist violence, was voted the country’s second-best politician in three separate polls. In France, the extreme-right Front National consistently grabs 15-20 per cent of votes, with similar numbers in Austria and an alarming near-30 per cent in Switzerland.

The situation is volatile, but not helpless. European political culture needs to change. There need to be frank debates over what to do about immigrant communities that underperform (many don’t). Solutions from both left and right political views could be implemented, such as welfare and immigration reform, linking welfare to school attendance, and community services in minority languages.

As it stands, the only people having engaged in this debate are extreme-right radicals. And if rising minority populations don’t feel welcome in their own countries of birth, they’re likely to turn to radical extremism against their compatriots.

Now is the time for mainstream European parties to speak openly about these sensitive issues and find workable, humane solutions. Otherwise populations on both sides risk becoming polarized and radical.