Terrorists. Belgium born french citizen Salah Abdelsalam. Isis has of course claimed responsibility for the atrocities committed here on friday. And according to cnn french affiliate bfm, six of the paris terrorists spent time in syria. Six of the eight. Two isis members are thought to have masterminded the terrorist attacks. They are believed to be in iraq or syria. Well have more on them later. Today in france president Francois Hollande said france must change its constitution to triegt to fight terrorism more effectively. And president obama at the g20 summit in turkey called the paris attacks a sickening setback, but he insisted his military strategy to destroy isis is not changing. There had been a few who suggested that we should put large numbers of u. S. Troops on the ground. It is not just my view but the view of my closest military and civilian advisers that that would be a mistake. Throughout his remarks, president obama stressed his belief that the United States cannot turn its back on Syrian Refugees even as more than a dozen states back in the United States slammed the door on that possibility today. All of this coming just hours after isis released a chilling new video warning washington, d. C. , youre next. Cnn Senior International correspondent Clarissa Ward is also in paris. Clarissa, police apparently let their man get away in the hours after the attack. Now they have still not been able to detain Salah Abdelsalam. What do your sources tell you about what authorities think . Do they think hes still in france . Do they think he might have slipped into pbelgium . Where might he be . Thats really the Million Dollar question, jake. It appears from the raids they dont necessarily know. What we do know is just a few hours after the attack French Police did stop and question Salah Abdelsalam. They decided that there was nothing more to discuss and he was allowed to go on his way. He was believed to be driving towards the belgium border. And then of course this morning we saw that massive raid in a brussels suburb. Seven people arrested in that raid. Five of them subsequently released, including the brother of Salah Abdelsalam. Also the brother of one of the bombers who blew himself up in the bataclan theater. He said that he knew nothing about these attacks, that he knew nothing about his brother who blew himself ups involvement and also new nothing about the whereabouts of Salah Abdelsalam who is now the primary suspect as being possibly the eighth attacker. But the manhunt continues. And its not limited to belgium. Its across france too, jake. Clarissa, elite members of the French National guard, the preferential National Police rather swarmed cities across the nation of france last night. They rounded up potential terror suspects. Do we know right now if any of those operations were directly connected to friday easter ror attacks . And can we expect even more of these raids in the coming days and weeks . I think we can certainly expect, jake, to see more raids in the coming days and weeks. Because while the primary focus might be currently on trying to find that eighth attack who are is still at large, there is a larger search going on here. A larger search to drill down on the network that must have existed to facilitate and help orchestrate attacks of this level. So French Police went on more than 150 raids today. They arrested 23 people. More than 100 people under house arrest. They found weapons including a rocket launcher. They found military clothing. And essentially theyre really trying to canvass the entire country to make sure this doesnt happen again, to try to get a better concept of who this network is and how it was functioning. As president Francois Hollande said, it was executed here in france, but it was orchestrated elsewhere. A lot of doors to knock on, jake. Clarissa, ward, thank you so much. Cnn chief National Security correspondent jim sciutto joins me now in the Place De La Republique, a massive makeshift memorial to the 129 victims. Jim, do police have a working theory as to how the terrorists put this nefarious plan into place last friday . They do. Sadly one of the headlines the terrorists put this plan into place with people that the police were aware of, several of them were on police radar. Thats one thing. Two, that they used belgium as kind of a staging area for this taking advantage of belgium that has fewer counterterror resources than france does. But then also that the trail leads all the way back to syria and they have a good idea now of not just one but two masterminds of this attack, one of whom and this is significant, goes right up to close relationship with the isis leader abu bakr al baghdadi. This say french officials is one of the possible ring leaders of the paris attacks. Heard saying in this terror video he enjoys spilling the blood of infidels. He is Abdelhamid Abaaoud a close leader of abu bakr al baghdadi. Frances former top counterer terror judge. This guy is actually very close to the chief, of baghdadi himself. For me, this huge attack has been issued or approved by Abdelhamid Abaaoud himself. Now isis is threatening to bring bloodshed to the streets of the u. S. Translator i swear to god a similar day that france went through you will go through. I swear to god as we struck france and its stronghold, paris, we will strike america and its stronghold, washington. Reporter today cia director john brennan said the u. S. Is taking the threats seriously. I would anticipate that this is not the only operation that isil has in the pipeline. And Security Intelligence services right now in europe and other places are working feverishly to see what else they can do in terms of uncovering it. Reporter as the u. S. And europe prepare for more plots, france is now counting the missed signals for fridays deadly rampage. At least two of the attackers were known to French Police, one for terror offensives, the other for being radicalized. Six of the attackers are believed to have traveled to syria and return to europe. One crossed along with thousands of Syrian Refugees through a major migrant entry point in greece. In addition the suspected ring leader abaaoud seen on the right was directing an attack by these two isis fighters who were later killed in a shootout with Belgium Police in january. But french Authorities Say they are simply overwhelmed. Today the list of suspected terrorists and others whove been radicalized in france has grown to some 11,000. We know that french citizen coming back from syria that might be a threat against french citizen. We also know french citizen in france that have never been to syria or to iraq that might also be a threat against french citizen. Reporter there are now hard questions here in france about whether frances terror Surveillance System is simply broken. You have these 11,000 names, jake. 5,000 suspected for terror connections. Another 4,000 or so for radicalization. They have Different Levels of monitoring, but the fact is they cant monitor all these people. And you do have and this has become part of the president ial campaign because the person speaking right then is a conservative candidate for president who is talking about what is in effect preventive detention. That you should take some of these guys before they even commit terrorism. And ill tell you in the last 24 hours youve had more than 100 raids. You now have 100 people under house arrest in france. They havent committed terror offenses, but in light of the Terror Threat right now, that is very much and across the globe. We have cnn counterterrorism analyst phil mudd, cnn National Security analyst and former congressman mike rogers, former chairman of the house Intelligence Committee. And with me here in paris cnn terror analyst paul cruickshank. Congressman, let me start with you. Isis claims to have blown a russian passenger jet out of the sky, killed scores of innocent people in beirut with suicide bombs, and now this horrific massacre in paris. Do three external operations in rapid succession represent a change in strategy for the terrorists . Or is it just now theyre capable of it . Its probably a little bit of both. Operations all had a thread back to syria in some way. So they planned an external operation from syria and made them happen in third countries, in egypt, in lebanon, now in france and paris. So that in and of itself is a change that theyve been telling us theyre going to engage in for some time. And if you remember, jake, the big fight between zawahiri, head of al qaeda and Isis Baghdadi was not about the brutality of their tactics. It was that baghdadi wanted to attack europe. He was very aggressive about wanting to get operations from syria into europe. They split over that because zawahiri wanted him to stay focused in syria. Youre seeing the fruit of all of that planning, all of that training and lots of space to operate. As a matter of fact a state the size of indiana they have the option to plan these type of events, recruit, train and then now deploy operatives to these countries. Thats a change thats concerning. Phil, you used to be a top official of the cia. Cia director john brennan today with some very sobering words, basically the u. S. Top spy that other isis plots are already in the works. How concerning an admission is this . You got to look at this as pretty high spectrum. The reasons are simple. Look at a couple characteristics of groups you have to focus on. In nearly 15 years of post9 11 plotting, weve seen plotting in africa, asia, middle east. Characteristics here are unique. Thats a group thats had time to plot. Theyve been in place now for a year, two years, three years. Unrest started in syria in 2011. Number two, leadership that has said it is their intent to attack overseas. Number three, a leadership thats been successful as mike rogers said in egypt, lebanon, france. And the final and most disturbing point if youre looking at the United States is the numbers game. If youre talking about hundreds of people from canada and the United States traveling overseas to fight, youve got to assume that there are thousands left behind who are viewing this who are sympathetic who have not had the courage, the money, the intent to travel yet. And sitting in their room tonight saying maybe i should do the same thing. There are a lot of characteristics for isis that put them on the top of the list, jake. Paul cruickshank, a source close to the investigation told cnn that this man, Abdelhamid Abaaoud is the mastermind behind the terrorist attacks. You see him featured here in the isis magazine dabiq. What do we know about him . Hes a very capable operational planner who is also thought to be behind that plot thwarted in belgium in january, a gunman similar plot to the one we saw play out in paris. Hes a belgian mo ro can traveled to syria in 2013, moved up the isis hierarchy and has been playing this key operational role for them, the kind of sheik mohamed role good at persuading troops to launch attacks and Training Organization and been a point communicating. The concern is hes plotting a string of attacks against france, against europe, jake. Paul cruickshank, phil mudd, congressman, stick around. When we come back we have much more on this story. An increase in security in the United States as this brand new isis video threatens washington, d. C. , by name Law Enforcement officials right now reacting to that specific threat. That story next. The possibility of a flare swas almost always on my mind. Thinking about what to avoid, where to go. And how to deal with my uc. To me, that was normal. Until i talked to my doctor. She told me that humira helps people like me get uc under control and keep it under control when certain medications havent worked well enough. 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Isis threatens the United States saying essentially youre next. As we speak Police Departments in major cities throughout the United States such as new york city, washington, d. C. , are ramping up their patrols. Today the director of the Central Intelligence agency said paris, france is not the only target that the terrorist group isis has in the pipeline. His comments came just as isis put out a chilling new video threatening to strike america and specifically mentioned the nations capital, washington, d. C. But the feds are treating the claims as a scare tactic. That of course is not stopping Law Enforcement from closely monitoring potential threats to the United States. I want to bring in cnns deborah feyerick. Deborah, do headquarters Police Departments throughout the country see the isis threat as legitimate . Well, you know, what they know is isis tends to put out these videos, sort of aspirational videos, but theres always the risk they could go from aspirational to operational. Thats really what theyre protecting against. So there is an increased awareness. It doesnt mean that the threat level has gone up. What it does mean is theres a hypersensitivity to anything that might appear out of the normal. In its latest video isis continues its threats against the west setting its sights squarely on the United States. Translator we will strike america and its stronghold, washington. Cia chief john brennan today warned the terror group now has a lethal external operations agenda. And what happened in paris will likely be attempted elsewhere. So i would anticipate that this is not the only operation that isil has in the pipeline. Following the attacks in paris, Police Departments in several major cities across the United States have ramped up security. In washington, d. C. , metropolitan Transit Police stepping up patrols on Public Transportation using bomb sniffing dogs and additional bag screening. In new york city 200 highly trained elite counterterror forces deployed to protect crowded places. A force that will ultimately total 500 tactical officers. The assignment for which you have volunteered, that assignment is now no more essential assignment in the world of policing. Socalled soft target venues are also increasing security. The nfl which already uses counterterror tactics like metal detectors and bag screening asked its members to further tighten its efforts. The cia director acknowledged isis has learned how to stay off the grid to help avoid detection. The attorney general said today these encrypted communications are a major concern. We are pursuing a number of options. Were in discussion with industry looking for ways in which they can lawfully provide us information while still preserving privacy. And the Justice Department estimates that there are about 250 people who have gone to syria andttempted to go to syria and iraq, some stopped before they were able to get there, others got there and killed. But they take the threat extr e extremeextrem extremely seriously. I spoke