"Meanwhile, refugees are still heading into Germany -- at a rate of around 10,000 a day. ... The decade after Ms. Merkel first came to power in 2005 now looks like a blessed period for Germany, in which the country was able to enjoy peace, prosperity and international respect, while keeping the troubles of the world at a safe distance. That golden era is now over." — Gideon Rachman, Financial Times .

"The migration crisis has the potential to destabilize governments, countries and the whole European continent. ... What we have been facing is not a refugee crisis. This is a migratory movement composed of economic migrants, refugees and also foreign fighters" — Hungarian Prime Minister Viktor Orbán.

"We need to be clear that there must be limits and quotas for immigration -- we cannot save the whole world." — Markus Söder, Finance Minister of Bavaria.

"We are importing Islamic extremism, Arab anti-Semitism, national and ethnic conflicts of other peoples, as well as a different understanding of society and law." — From a leaked German intelligence document.

Germany's Muslim population is set to nearly quadruple to an astonishing 20 million within the next five years, according to a demographic forecast by Bavarian lawmakers.

The German government expects to receive 1.5 million asylum seekers in 2015, and possibly even more in 2016. After factoring in family reunifications -- based on the assumption that individuals whose asylum applications are approved will subsequently bring an average of four additional family members to Germany -- that number will swell exponentially. This is in addition to the 5.8 million Muslims already living in Germany.

According to the president of the Bavarian Association of Municipalities (Bayerische Gemeindetag), Uwe Brandl, Germany is now on track to have "20 million Muslims by 2020." The surge in Germany's Muslim population represents a demographic shift of epic proportions, one that will change the face of Germany forever, "but we are just standing by, watching it happen."

Addressing an expo in Nuremburg on October 14, Brandl warned that untrammeled migration will entail heavy costs for German taxpayers and may also lead to social unrest. He said:

"A four-member refugee family receives up to 1,200 euros per month in transfer payments. Plus accommodation and meals. Now go to an unemployed German family man who has worked maybe 30 years, and now with his family receives only marginally more. These people are asking us whether we politicians really see this as fair and just."

Brandl said this also applies to the electronic health card, which provides asylum seekers with the same benefits as Germans who have paid into the health insurance system for many years. To criticize this as unfair has "nothing to do with racism or right-wing extremism."

Brandl's concerns are echoed in a leaked intelligence document, which warns that the influx of more than one million migrants from the Muslim world this year will lead to increasing political instability in Germany.

The document -- portions of which were published by Die Welt on October 25 -- reveals growing alarm within the highest echelons of Germany's intelligence and security apparatus about the consequences of Chancellor Angela Merkel's open-door immigration policy.

The so-called non-paper (the author of the document remains anonymous) warns that the "integration of hundreds of thousands of illegal migrants will be impossible given the large numbers involved and the already-existing Muslim parallel societies in Germany." The document adds:

"We are importing Islamic extremism, Arab anti-Semitism, national and ethnic conflicts of other peoples, as well as a different understanding of society and law. German security agencies are unable to deal with these imported security problems, and the resulting reactions from the German population."

An unidentified high-ranking security official told Die Welt:

"The high influx of people from other parts of the world will lead to the instability of our country. By allowing this mass migration, we are producing extremists. Mainstream society is radicalizing because the majority does not want migration, which is being forced by the political elites. In the future, many Germans will turn away from the constitutional state."

The warnings come amid mounting criticism of Merkel, whose September 4 decision to open the door to migrants in Hungary exacerbated the crisis.

The Minister-President of Bavaria, Horst Seehofer, who also heads the Christian Social Union (CSU), the sister party to Merkel's Christian Democratic Union (CDU), has emerged as one of Merkel's most vocal critics. "I am convinced that the chancellor has chosen another vision for Germany," he said. "This has been a mistake that will occupy us for a long time. I see no way of putting the genie back into the bottle," he added.

In an interview with Bild, Seehofer said:

"We explicitly believe that immigration must be controlled and limited if Germany wants to cope with it. The seriousness of the situation is becoming clearer every day. The population does not want clever sayings or inconclusive site visits. It wants action!"

After months of attacking critics of Merkel's immigration policies as right-wing xenophobes, Vice Chancellor Sigmar Gabriel and Foreign Minister Frank-Walter Steinmeier conceded that the migration crisis risks tearing German society apart. In a joint essay published by Der Spiegel, the two wrote: "We cannot indefinitely absorb and integrate more than one million refugees each year."

Bavarian Finance Minister Markus Söder said: "We need to be clear that there must be limits and quotas for immigration — we cannot save the whole world. The refugee influx will not be stopped unless we secure our borders and send a clear signal that not everyone can come to Germany."

Former Interior Minister Hans-Peter Friedrich (CSU) described Merkel's immigration policy as an "unprecedented political blunder" that will have "devastating long-term consequences." He said the job of politics is to think beyond the present and make decisions for the future. In view of the massive flows of migrants into Germany without any police checks, Friedrich concluded: "We have lost control." He added:

"It is totally irresponsible that tens of thousands of people are flowing into the country uncontrolled and unregistered, and we can only unreliably estimate exactly how many of them are Islamic State fighters or Islamist sleepers. I am convinced that no other country in the world would be so naive and starry-eyed to expose itself to such a risk."

CDU lawmaker Michael Stübgen said: "The disagreement [with Merkel] is fundamental. Our capacities are exhausted and there is concern that the system will implode if we do not regain control of our borders. But the chancellor disagrees and so the conflict is unsolved."

On October 21, more than 200 mayors in North-Rhine Westphalia signed an open letter to Merkel, in which they warned they were no longer capable of taking in any more migrants. The letter states:

"We are seriously concerned for our country and the cities and towns we represent. The reason: the massive and mostly uncontrolled flow of migrants to Germany and our cities and towns. "All available housing possibilities are exhausted, including tents and shipping containers. Managing the migrant shelters is so time intensive that our personnel can no longer attend to other municipal responsibilities."

Speaking at an October 22 gathering of the European People's Party in Madrid, Hungarian Prime Minister Viktor Orbán warned of the consequences of Merkel's immigration policies. He said:

"We are in deep trouble. The migration crisis has the potential to destabilize governments, countries and the whole European continent.... "What we have been facing is not a refugee crisis. This is a migratory movement composed of economic migrants, refugees and also foreign fighters. This is an uncontrolled and unregulated process.... I also want to underline that there is an unlimited source of supply of people, after Syria, Iraq, Pakistan, Afghanistan, Africa is now also on the move. The dimension and the volume of the danger is well above our expectations.... "Our moral responsibility is to give back these people their homes and their countries. It can't be our objective to provide them with a new European life. Right to human dignity and security are basic rights. But neither the German, Austrian nor the Hungarian way of life is a basic right of all people on the Earth. It is only a right of those ones who have contributed to it. Europe is not able to accept everyone who wants a better life. We have to help them to get back their own lives with dignity and we have to send them back to their own countries.... "We cannot avoid speaking about the quality of our democracies. Is it freedom of information and speech when the media usually show women and children while 70% of the migrants are young men and they look like an army? How could it happen that our people feel that their opinion is not being taken into consideration? And we have to address the question of whether our people want what has been happening. Did we get authorization from them to allow millions of migrants to enter our continent? ... No, distinguished delegates, we did not. "We cannot hide the fact that the European left has a clear agenda. They are supportive of migration. They actually import future leftist voters to Europe hiding behind humanism. It is an old trick but I do not understand why we have to accept it. They consider registration and protection of borders as bureaucratic, nationalist and against human rights. They have a dream about the politically constructed world society without religious traditions, without borders, without nations. They attack core values of our European identity: family, nation, subsidiarity and responsibility."

In an October 26 column for the Financial Times, titled "The End of the Merkel Era is Within Sight," Gideon Rachman wrote:

"The refugee crisis that has broken over Germany is likely to spell the end of the Merkel era. With the country in line to receive more than a million asylum-seekers this year alone, public anxiety is mounting — and so is criticism of Ms. Merkel, from within her own party. Some of her close political allies acknowledge that it is now distinctly possible that the chancellor will have to leave office, before the next general election in 2017. Even if she sees out a full term, the notion of a fourth Merkel administration, widely discussed a few months ago, now seems improbable... "The trouble is that Ms. Merkel's government has clearly lost control of the situation. German officials publicly endorse the chancellor's declaration that 'We can do this'. But there is panic just beneath the surface: costs are mounting, social services are creaking, Ms. Merkel's poll ratings are falling and far-right violence is on the rise. "As the placid surface of German society is disturbed, so arguments about the positive economic and demographic impact of immigration are losing their impact. Instead, fears about the long-term social and political effect of taking in so many newcomers — particularly from the imploding Middle East — are gaining ground. Meanwhile, refugees are still heading into Germany — at a rate of around 10,000 a day. (By contrast, Britain is volunteering to accept 20,000 Syrian refugees over four years.)... "Some voters seem to have concluded that Mutti [a German familiar form of 'mother'] has gone mad — flinging open Germany's borders to the wretched of the earth... "The refugee crisis marks a turning point. The decade after Ms. Merkel first came to power in 2005 now looks like a blessed period for Germany, in which the country was able to enjoy peace, prosperity and international respect, while keeping the troubles of the world at a safe distance. That golden era is now over."

Soeren Kern is a Senior Fellow at the New York-based Gatestone Institute. He is also Senior Fellow for European Politics at the Madrid-based Grupo de Estudios Estratégicos / Strategic Studies Group. Follow him on Facebook and on Twitter. His first book, Global Fire, will be out in early 2016.