Don Lemon: A worldwide manhunt underway tonight for terror suspect, Salah Abdeslam, just seven days after the devastating Paris terror attacks shocked the world.

Joining me now is Alan Dershowitz, the author of a new book called "Abraham, the World's First But Certainly Not the Last Jewish Lawyer." Interesting title. And also with me is Pete Hoekstra, the former chairman of the House Intelligence Committee.

I can't wait to talk to you, gentlemen. Thank you so much for joining us. Pete, I'm going to go to you first. You know, it's now exactly one week, I can't believe it, from those heinous attacks on Paris. Has the world significantly changed in one week?

Pete Hoekstra: Oh absolutely. You know, the process started really two and a half weeks, three weeks ago, when you had ISIS taking down the Russian plane over the Sinai Peninsula, then you had the bombings in Beirut, and then you have what happened in Paris. And then since that time, you know, you've had the aftermath in Paris, you've also had the attack in Mali. The world is a very, very different place and no one is sure what it looks like or what the threat environment is today.

So, everybody is kind of hopefully listening and learning as to how we can move forward and keep, you know, multiple countries safe at this time.

Lemon: A lot of people are telling me that they are listening this, Mr. Hoekstra, and learning on the street and people are telling me, today, I was with Ben Stiller and he said every night I watch and I learn from you know, the panels and the people you have on. The world is learning. Sadly, these things are happening. But we're all learning together, aren't we?

Alan Dershowitz: Yeah, and I think it's very important. It's an expensive way to learn. Because the cost of human life has been so high. But we have to learn. We have to change.

Lemon: The French President, Francois Hollande said that they are at war with ISIS. And I've heard some say, Alan, that that this is the beginning of World War III. Do you believe that?

Dershowitz: No, that's a very Eurocentric view. Look, we've been at this war now for 30 years. You look at Israel; they've been fighting terrorism now for many, many, many years, airplane hijackings, thousands of people killed in terrorist attacks. But when it comes to Paris we pay far more attention because we are so much more closely identified with European countries and we fear what will happen here.

It's not a war. We have to understand that. We know how to fight wars and we always fight the last war. This is a very different phenomenon. We have to develop very different techniques, and specially this is a new phenomenon using new technologies.

We've seen nothing until we see the internet starting to be hacked, until we see, you know, the whole structure being subject to terrorism. We have to learn how to fight the next war not refight the last one.

Lemon: Someone ask me, Mr. Hoekstra, we are -- Mr. Hoekstra, we are learning tonight that the Paris attackers, Salah Abdeslam, his record was clean enough to allow him to enter -- entry into this country. Do we need to add extra security in our screening process here of security screening?

Hoekstra: I think you do need to add more screening here. But let me disagree a little bit with what Alan was just talking about. You know, if we don't actually start confronting threats today, it's going to start looking a lot more like a war.

We have ISIS now that controls a geographic area in Syria and Iraq that is close to the size of the State of Indiana. That we have other caliphates, you know, their threat is environment is evolving to cyberspace which right now they've been using for recruiting purposes and messaging purposes.

But I fully expect that one of these days we're going to see a cyber-attack coming from -- from ISIS and so, yes, I think we're approaching that scale where it's going to be a war. But Alan is correct, it's going to be a very, very different war.

In regards to, you know, talking about upping screening, we need much better coordination at all levels of intelligence. You know, our terrorism centers at the regional levels need to be better coordinated with the FBI. The FBI needs to be better coordinated with the CIA. And then the CIA needs to be better coordinated with other intelligence services around the world.

Lemon: You said a cyber-attack. In what way do you fear?

Hoekstra: I fear that they'll go after our infrastructure. You know, they can shut down, you know, they could shut down perhaps some power plants. They could go after a financial center. There are all kinds of areas where the United States is very, very vulnerable to a cyber- attack.

They're trying to develop those capabilities, and just like we're listening and learning, they are also listening and learning and cyber is a, you know, it's a poor man's tool. You need the knowledge, but you can attack the West or not your enemy with a very small investment. You just need to be very smart.

Lemon: And is that a bigger threat, you think than the type of attacks that happened in Paris?

Dershowitz: I think it's a greater existential threat to the country. I think that, you know, killing people over Christmas vacation or going into malls or going into theaters or Grand Central Station, dramatically we react to it much more because we see the human life before us.

But cyber-attacks can really bring the country to an economic halt, to a medical halt. It can really devastate. We have to be prepared for those kinds of attacks. Now it's not only ISIS. Look, the attacks today were not ISIS.

Lemon: Right.

Dershowitz: There is Al Qaeda. There are the other groups that don't have property.

Lemon: Boko Haram and all of those groups, right...

Dershowitz: And even if we win the war against the areas that ISIS attacks, there will still be ISIS cells and other -- in Europe and in the United States that can attack even without them having territory. So, it's a new type of a battle we are fighting.

Lemon: All right. Both of you, gentlemen, stay with me. In the wake of the Paris terror attacks the battle is heating up in the U.S. over refugees, and whether to let them in. That discussion is next.

Commercial Break...

Lemon: In the wake of the Paris terror attacks, the battle over refugees in this country really heating up. President Barack Obama meeting with Muslim refugees in Malaysia as the White House tries to shape the debate.

Back with me now is Alan Dershowitz and Pete Hoekstra. Again, great conversation. Thank you so much for coming in. As a crusader, Alan, you're a crusader against anti-semitism, what comes to mind when you hear this recent anti-refugee rhetoric?

Dershowitz: Oh, there is no question. I remember my parents telling me that, you know, the 1930's when Roosevelt turned away the St. Louis with almost a thousand Jewish refugees from Germany...

Lemon: Nine hundred on there and 200 were killed...

Dershowitz: Yes. Right, right. And, you know, the Canadian foreign minister said, even one is too many, they wouldn't take in. So, we have to open our gates. We have to become the ultimate country of asylum. But, we shouldn't conflate two issues.

The first most important issue is to get them out of harm's way, get them out of Syria, make sure the kids don't drown, they're safe. Get them out. That's the first thing. If they could go to some place like Saudi Arabia, which has enormous land mass, very few people; could stay there until the situation is resolve and then go back to Syria and help build the country, that would be ideal.

But if that can't happen...

Lemon: Saudi Arabia doesn't want to.

Dershowitz: ... we have to be the country of last resort. But the Arab countries and the Muslim countries should be the first ones. And we should be putting pressure on them to take them, hold them at least temporarily until the crisis abates.

But if nobody else will take them, hey, that's Statue of Liberty means something. We have to take them in.

Lemon: Are you -- do you have concerns about letting Syrian refugees into the country, Peter?

Hoekstra: I do have concerns about that. When you're talking about this, and, you know, I'm well -- well aware of what this process is from the time that I spent on the intelligence committee.

You know, you were looking at ungoverned areas. And what that means is there is not a central government database where we can get information on who these people are, what their backgrounds are and these types of things.

So, it's a garbage-in data system. Garbage-in it means garbage-out. We can't vet these folks. I think Alan is exactly right. Get these folks out of harm's way, you know, roll back the area that ISIS controls and then let these folks go back home and rebuild their communities.

The Kurds just did this in Iraq. They freed Sinjar Mountain and Sinjar City. That was an area that 400,000 people used to live in. This is now an area where 400,000 people should be able to be -- should be able to move back into and start rebuilding.

Lemon: Yes, but I wonder. If this is a real fear, though. If it's a real fear, if none of the Paris attackers, if they were not Syrian, if they didn't come over as part of the refugee process. What type of -- is a fear that is unreal being stoked here in the United States is my question?

Dershowitz: Well, I think it's partly real but it is always exaggerated.

Lemon: Yes.

Dershowitz: And it becomes generalized. An anti-Muslim fear. And we can't allow that kind of bigotry to operate. We can't generalize about people based on their religion. What we have to do is make individualized determinations. Certainly make the children -- let the children come in first. That's the first rule. But save everybody first, then we can deal with permanent residency and citizenship. That comes second.

Lemon: Thank you, gentlemen. I appreciate it. Have a safe weekend to both of you.

Dershowitz: You, too. Thank you.

Hoekstra: Thank you.

Lemon: Thank you. We'll be right back.