Leader comment: Merkel must not cave in under political pressure

The attack on the Berlin Christmas market is particularly abhorrent, because of the place and because of the time, but it was deliberately planned and timed to have greater impact, to provoke greater revulsion and anger, because that is the nature of the perpetrators we are dealing with.

German chancellor Angela Merkel arrives at a Christmas market in Berlin the day after a truck was driven into the crowd killing 12 people. Picture AP

Our thoughts must be with the loved ones of the 13 who were killed, including those of the Polish lorry driver, and the injured, particularly the 18 who are in a serious condition. But this outrage can come as no surprise: we know the tactics of the attackers, we know that everyday objects like lorries can be turned in to weapons, we know that any crowd is a target, and we know that no city in Europe is safe from such attacks.

It is not clear yet if this was the work of Islamic State (they were very quick to claim responsibility after the atrocity in Nice) , and we know that none of the perpetrators have been caught. The suspected asylum seeker from Pakistan initially held by the authorities denied any involvement and has since been released. It seems probable now that the real lorry driver was killed when his vehicle was taken, and it is telling that the weapon used to shoot him has not been recovered. That always indicated that there was another person or people involved and they are still at large.

The fact Islamic State has not yet claimed responsibility means nothing and actually illustrates the difficulty of dealing with the current threat. There are no great logistics required, there is little specialist knowledge required, there is no co-ordination of effort required. This could have been done in the name of IS and for that cause with the actual organisation having no knowledge. They have appealed for supporters to rise up, they can do so with no contact whatsoever, and that is why these attacks are so hard to prevent through intelligence-gathering.

But that does not mean we are powerless in the face of such onslaughts. In Germany the authorities have already started moving large concrete blocks on the approaches to Christmas markets. Perhaps part of the price we all have to pay for this is more roads closed to vehicles in city centres. This will never prove to be 100 per cent effective, but it will help, and might force a change in tactics from the attackers.

And we are all going to have to be more aware of potential threats and prepared to alert the authorities if we believe something to be wrong.

German chancellor Angela Merkel has come under fire for her open attitude to refugees, and she has said that if this attack was indeed carried out by an asylum seeker then “it would be particularly difficult for us all to bear”. But it is very likely that the people capable of carrying out these acts will go through the motions of claiming asylum. They are seeking to infiltrate the West, but making it harder to come in will not mean such attackers will not get in.

Political pressure will be brought to bear, but Germany should not change its stance.