DW: In response to the November 2015 Paris terror attacks, tightened security controls are to be implemented as of now at the Schengen zone's external borders - for EU citizens as well. Is everyone under general suspicion?

Elmar Brok: No, but I think that controlling our exterior borders is the right thing to do in light of the threat posed by terrorists. Controls must be put in place. And that is the plan: Control the external borders to ensure interior freedom - that must be our guiding principle.

Do you believe that Schengen states can implement these new rules? The entire procedure is rather complicated.

I think they can. That is also why some states, such as Bulgaria and Romania, are not yet Schengen states - they have been unable to fulfill certain criteria. They still have work to do. We all have to be prepared to better protect the borders of the European Union if we want to keep interior borders open while we are engaged in the fight against terrorism.

Critics are convinced that such controls represent the loss of one of the European Union's most important achievements.

No, the EU's achievement is an open interior. I still have freedom of movement within the European Union. But the exterior borders must be protected. You can't tell who is an EU citizen just by looking at them.

But controls along interior borders are also constantly being talked about. So there are those who object to the current move, saying it is a stepping stone to tighter interior controls.

I would be strongly opposed to such controls. That would be a contradiction. Exterior protection guarantees interior freedom. In individual cases, interior controls can also be carried out if there is evidence of an imminent threat. That has always been the case - for example when controls were set up to keep British hooligans out during the 2006 Wold Cup. That must be allowed on a case-by-case basis. Controls can be carried out within the EU as well, regardless of borders. For instance, German police can enter the Netherlands in order to pursue suspects. That is all part of the Schengen agreement. That may mean that there are many more controls, but it also means that everyday citizens have much more freedom.

Let's look at how the new rules are to be put into action: EU citizens' identities will be checked against current wanted lists. In the past, there have often been flaws in communication between authorities in individual member states? What is the state of cooperation right now?

I think the current Schengen communication system can fulfill the technical requirements. But in the recent past we have seen that problems even exist between the computer networks in individual German states. For instance, when an immigrant was registered in Bavaria, authorities in Schleswig-Holstein had no idea. Thus, people like Anis Amri (the Berlin Christmas market attacker) could use several identities to travel around the country, because communication between different municipal authorities and German states didn't work. I believe that there has been a lot more pressure to fix that problem in the European Union over the last few months and years. That lets us protect against criminals, while at the same time guaranteeing the freedom of EU citizens who act as they are supposed to.

Is this type of intensification the right reaction to the type of terrorism that we are now confronted with? Authorities repeatedly warn about attacks by so-called "lone wolves."

Nothing can guarantee total safety. Such measures may limit the scope of terrorists, but they do not rid us of the threat altogether. Border patrols and coast guards must be strengthened, and we have to improve cooperation among domestic intelligence services in order to apprehend such "lone wolves." We will never be totally protected against violent criminals that are operating as suicide attackers. But it is the responsibility of the European Union to limit them as much as possible. The enhancement of controls on the Schengen area's exterior borders will help to achieve that.

Elmar Brok (CDU) is a member of the European Parliament. With some interruptions, he was also chairman of its Committee on Foreign Affairs, of which he is still a member, for almost 13 years until January 2017.

This interview was conducted by Friedel Taube.