A national opinion poll taken here between December 5 and January 7 has revealed the concerns that many Irish people have about the number of refugees who will be arriving here over the next few years. Ireland has agreed to take in 4,000 refugees (plus eventual family reunions), and a sizable number of them will be arriving this year.

Nearly half of the people questioned in the poll for the Sunday Independent newspaper think we are taking in too many refugees, and more than half are worried there may be terrorists among them. In the wake of what happened in Paris and elsewhere, including San Bernardino, that fear is understandable, although it is already being dismissed by immigrant support groups and advocates of multiculturalism as groundless, ignorant and even racist.

It seems likely, however, that if the thousand-plus people questioned across Ireland for this poll had known about the sex attack rampage carried out by immigrants in the German city of Cologne on New Year's Eve, the results would have shown an even greater level of concern. Instead of the poll showing around half of people here being worried about taking in refugees, the number probably would have been even higher.

But people here did not know about Cologne because the news about the attacks was suppressed for several days and the poll in Ireland was almost complete before the truth of what had happened there emerged.

When it did come out it became a major story across Europe as well as in Ireland, which is not surprising given the horrific details.

People in Cologne always gather in the square in front of the Cathedral to welcome in the New Year. In Dublin, crowds of people gather near ChristChurch Cathedral to do the same and listen to the church bells at midnight. Similar gatherings happen in cities around the world.

This New Year's Eve in Cologne was different, however. What should have been a joyous event welcoming in the New Year turned into a nightmare well before midnight.

A crowd of over a thousand men, mostly of Arabic and North African appearance (the police description), had gathered in the square, and many of them were aggressive and either drunk or high. They began throwing bottles and firecrackers around, and as people tried to move away to safety groups of them began surrounding and sexually assaulting women. Even women accompanied by boyfriends or husbands were mugged and groped by the mobs swirling around in the crush.

With only 100 police in the area, they were outnumbered and could do little to control the situation and stop the attacks. Women who managed to force their way out of the jam of gropers, which took some time, then ran in terror towards the nearby train station or down the crowded side streets towards the Rhine. They were pursued and surrounded, had their breasts squeezed and underwear torn off, and many ended up with bruised and scratched arms and thighs. Within a few hours at least two women had been raped.

What happened the next day was extraordinary, even by the usual standards of political correctness. Despite the night of mayhem, a Cologne police statement issued the following morning described the New Year’s Eve celebrations as “peaceful.” The German media that day did not report the extent of what had taken place the night before.

Both failures were later attributed to a refusal to accept that this could have happened on such a scale and, even if it had, an over-riding belief that it had to be minimized to avoid stirring up anti-immigrant sentiment.

But ordinary police officers knew the truth and were unhappy at the high level cover-up. An internal police report was leaked to the media which said that dozens of men had been questioned on the night, many of whom had residence permit papers identifying them as recently arrived refugees.

“In the forecourt and on the cathedral steps were a thousand people, mostly males of an immigrant background who were indiscriminately throwing fireworks and bottles into the crowd," the report said. "Women literally had to run the gauntlet through the mass of drunk men, in a way you can’t describe. Many women came to officers shocked and crying and reported sex assaults."

Despite the truth starting to seep out in the next couple of days, the Cologne police chief continued to caution against blaming a particular group before an inquiry could be carried out. But the cover-up lasted little more than a few days due to the outrage of women and the volume of complaints.

The day after New Year's Eve more than 170 women filed criminal complaints, the majority for sexual assault. Women who were in the square and in the surrounding streets on the night described it as absolutely terrifying and said that as they were being battered, groped and robbed they were called bitches and prostitutes.

The number of complaints filed has now passed 500, and nearly half are for sexual assault. The Cologne police chief resigned following criticism from a government minister of the way the policing of the celebrations had been organized, although this is another way of deflecting blame from those who carried out the assaults.

Even worse, after it had become clear that this was a mass sexual assault by hundreds of immigrants, the local mayor, a woman, advised that in the future women in Germany would need to be careful in situations like this and keep at least an arm's length away from men. The mayor, who also promised to produce "guidelines" for women in Germany, is still in office despite her comments.

As the full details of what happened in Cologne on New Year's Eve have become clear, some very basic questions about the implications of the arrival of so many refugees in Europe from North Africa are now being asked. It has since emerged that this did not just happen in Cologne on New Year's Eve but in several other German cities as well where young male immigrants also took part in mass sexual assaults.

Cologne was not an isolated event. There is a pattern which indicates underlying issues that need to be discussed.

What seems to have angered many Germans is the sense of betrayal they feel, having opened their borders and taken in over a million refugees in the past year. Having shown such generosity to the refugees, how could some of them have behaved in such an appalling manner?

This sense of betrayal was exacerbated by reports that some of the refugee gropers had told police that they could not do anything to them because they had been "invited to Germany by Mrs. Merkel." They tore up their refugee identity papers, boasting to police they could easily get new ones.

Apart from the lack of any gratitude, this contempt for the system was shocking for many Germans, even for all the younger idealists who have been so emotionally involved in trying to help refugees. A lot of very naive preconceptions were suddenly getting a rude awakening.

Among the issues involved in all this is the very high number of young men among the refugees who have arrived in Europe, even though the media always concentrate on pictures of families or children. The vast majority of those who forced their way across barriers as they tramped their way up through Europe, ignoring all immigration rules, were young men.

They came not just from Syria or its neighboring countries, but from other countries in North Africa and sub-Saharan Africa. Many appeared to be economic migrants rather than refugees fleeing the Syrian war in fear of their lives.

Some time ago this column looked at the pros and cons of the rescue missions being conducted by the Irish Navy in the Mediterranean and

pointed out that one such rescue had saved around 320 migrants from leaky boats, but around 300 of them were young men.

The immediate liberal response to this point is to claim that this always happens in emigration flows, that young men go first and later other family members follow. Irish emigration to the U.S. and the U.K. is cited as an example.

But that’s simply not true. Over the past century young Irish women and men emigrated in roughly equal numbers.

Added to this imbalance among the refugees are cultural differences. Many of these young men are from Arabic countries where women are expected to cover up and be subservient. These young men are not used to the equal status and freedom in dress and expression that women in Europe have, and they may misinterpret or resent that freedom and equality.

This problem is further complicated by religious differences in the way women are regarded. It is also complicated by the sudden availability of alcohol and an inflated sense of entitlement.

In general, what happened in Cologne on New Year's Eve has been a wake-up call to people in Europe who, like people in Ireland, have not been consulted by the politicians who have been taking decisions on the refugee crisis. In particular, it has been a wake-up call for many on the liberal left who have been forced to reconsider their idealistic and often simplistic thinking and accept that there are serious difficulties involved in all of this.

This will be important in the year ahead when another 1.5 million refugees are expected to arrive in Europe. With Germany now feeling that it has done its part and it is up to other countries to share the burden, where will they go?

One thing emerges clearly. British Prime Minister David Cameron's policy of selecting people in the Syrian refugee camps in Lebanon and Jordan now seems wise.

Those chosen to be given new homes in Britain will be those most in need, which will mean they will largely be families and children who have fled directly from the war in Syria and have lost everything. Ireland would do well to copy this wise policy.

Taking in refugees who have already forced their way into Europe only encourages even more to come. Those who arrived in Europe last year are not the most vulnerable.

The most in need are the young, the old and the weak among the millions left behind in the miserable refugee camps in Lebanon and Jordan.