The situation still incredibly tragic and incredibly fluid and very, very tense. Nearly four days after one of the darkest moments in that countrys history, a massacre of israeli civilians, it marks the single worst mass murder of jewish people since the holocaust. And some of his most extensive remarks since the start of the crisis, President Joe Biden condemned the attack and has pledged an all Hands On Deck effort to support israel. Watch. You know, there are moments in this life, i mean this literally, when the Pure Unadulterated evil is unleashed on this world. People of israel lived through one such moment this weekend. The bloody hands of the terrorist organization hamas, a group whose stated purpose or being is to kill jews. This is an act of sheer evil. More than one thousand civilians slaughtered. Slaughtered in israel. Among them, at least 14 american citizens killed. This is terrorism. But sadly, for the jewish people, its not new. This attack has brought to the surface painful memories and the scars left by a millennia of antisemitism and genocide of the jewish people. So in this moment, we must be crystal clear. We stand with israel. On the ground, the Israeli Government announced today that it has secured the border with gaza and that it has regained control over the communities in that area, which were the scenes of heinous and horrific attacks. With the u. S. Government describes as, quote, isis level savagery. At least 100 people right now are hostages of the Terrorist Group hamas, and that terror group promises to execute them in response to any attacks i gaza. The u. S. Government says that americans are among the hostages. Our colleague and the anchor of Nbc Nightly News lester holt spoke with nahar neta, whose 66yearold mom adrien hails from one of the communities on the front lines. He tells nbc that he is holding out hope that his mother is still alive. Watch. My brother called me again on the group call and i heard my sister screaming and crying on the phone. And my brother told me that they both heard Hamas Terrorists burst into the shelter in my moms home, and that was when the conversation was disconnected. Notably, there were no shots heard . There were no shots heard, yeah. So you take some hope in that . Of course. So my mom, she is a tough lady. Now the search for hostages and the Recovery Efforts take place of course against the backdrop of dangerous and deadly open warfare. Rockets fired by hamas seen in the skies above Southern Israel once again today. Our colleague Richard Engel was on the scene for that. Watch. Now were hearing it again. So, jose, stay with us. There is one. There is a rocket. You can see it streaking in the sky right now. Turning. There is another. This is being launched from a different site. So now youll start to see the Iron Dome System taking them off. Israel struck at targets in gaza as well, striking a port, as everyone in the country braces for prolonged warfare. In israel, a mobilization unprecedented in the countrys 75year history. 360,000 people have been called up to serve. Thats about 4 of the countrys population. An israeli general said that the military is, quote, preparing to go on the offensive to change the reality within gaza to prevent such a thing from happening again. The Israeli Government has already declared what it describes as a full siege of gaza in response to the Terrorist Attack and has asked the United States for more weapons. Thats where we start today a spokesperson from the National Security council john kirby. John, i know its been a long four days for you, and i just want to start by asking you how much more you know because of your position and your proximity to sources and methods that the General Public doesnt have in terms of what actually happened over the weekend in israel. Well, we know that this was a very complex attack and various lines of advance. Obviously it took months and months of planning. Very carefully thought out and resourced. Obviously, it took a lot of training for these Hamas Terrorists to be able to pull Something Like this off. Were still digging in to the intel picture, nicolle, and we dont have a perfect picture as to exactly how this was able to occur, all this training and all this preparation. And then to be executed. Were still working our way through that. But clearly, this was a complex attack that they were well prepared for. Someone said to me over the weekend, imagine if 9 11 instead of involving three sites and four planes had involved 13 cities with massacres of women and children, families slaughtered in front of their friends, sort of a slow motion Terrorist Attack. Is that an accurate description of what you understand the brutality of the Terrorist Attacks on the israeli people to have been . Yes, i do. I think thats a very eloquent way of putting it. The barbarity, the depravity, as the president said, the utter evil that these terrorists visited upon innocent Israeli Citizens. People out at a Music Festival, just in their homes, just living their lives. And there is all violence against innocent life is bad, of course. But when its up close and personal like that, when throats are being slit, when people are being rape and tortured, shot at pointblank range, there is a brutality to that, a visceral nature to that that i think is important for everybody to understand, as hard as that is to swallow, its important to understand how up close and personal and visceral this violence was and continues to be. What is the sort of behindthescenes work of the white house right now . Are you working on i know that Courtney Kube had some fantastic reporting over the weekend that the navy was sort of brainstorming perhaps moving some ships to help with some evacuations. I know that im sure you know this as well anecdotally, its hard to get out if youre an american and were there visiting family. Can you tell me what youre doing tactically to anyone that might be watching trying to help family or friends in the country . Well, the embassy is still open for business and providing Consular Assistance to any american citizens who want Additional Information or Safety Information or want information about how to leave israel. Were still up and running there at the embassy in jerusalem. I would also mention that of course the airport of ben gurion is still open, and air traffic is coming in and out every single day. Not all carriers are flying out of there, but most International Carriers are. So people who want to leave, can leave that way. There is also open ground routes out of the country. But a lot of people, nicolle, you know, theyre dual nationals. Israel is home as well, and they dont want to leave. They dont want to leave their homes and their families and their friends. So its understandable that there is going to be some mixed emotions there. But we are doing everything we can to provide the kind of information and context they should need should they want to come to that decision point. The Secretary Of State is traveling to israel tomorrow. What are his sort of key objectives for the mission other than listening and supporting as the president just said . Well, he will reiterate strongly how deeply america stands by israel. He will reiterate the president s messages in his meetings with his counterparts and to the israeli people that he will be the physical embodiment of course of the administration so shortly after these attacks and make it very clear that were going to continue to stand by them, that Military Assistance is already on its way. The First Tranche is already on its way, and im sure hell talk to them about additional tranches of Security Assistance and what that might look like and what schedule. Obviously were going to have to get feedback from the israelis about what they need and what quantity and that kind of thing. And i think hell also want to talk to the israelis about hostage Recovery Efforts. We know a number of americans are being held hostage. But so many israelis are as well, and people from other countries. Its not just one nation here affected by this hostagetaking. I suspect that the secretary will want to talk to the israeli counterparts what theyre thinking in terms of recovery of these hostages. What kind of support have we offered in terms of helping the hostages . We have offered initially the expertise, the advice and counsel of so many Hostage Recovery Experts here in the United States. We have terrific Hostage Recovery Expertise in Law Enforcement here in the United States, federal Law Enforcement, the Intelligence Community, the United States military. We have a lot of experience. Now we know, of course, israel too has a lot of experience at this. But were willing to share whatever we can with them. One of the sort of hallmarks of the period, and one of the times i think our viewers got to know you best, you were still at the pentagon in the walkup to russias invasion of ukraine, it was part of our Foreign Policy to declassify intelligence about what russia planned to do to our ally, ukraine. And i know this is completely different. Hamas is a terrorist organization. But i wonder if we had any sense that hamas had regrouped and restrengthened, and if we had any internal conversations about doing anything along the lines of what we did ahead of russias brutal invasion of ukraine . Its a great question. I want to be careful here to not get into intelligence matters. And i think its fair to say that there is going to be a time when were going to want to look back at the intel picture ourselves. I suspect the Israeli Government will do the same thing, to look back at the intel picture in the past tense and see what might have been missed, where and when, sort of stitch it together, and do the forensics so that we can make sure we have a more complete picture of what hamas is capable of going forward. That time is not now, though. Right now the time is really helping israel beat back this aggression and defend themselves, take action against hamas and make it more less feasible that they can do any more operations right now in the immediate term. Thats what the focus has got to be on, supporting israel. A lot of americans are voicing this real despair about the rise of antisemitism around the world and what the president i think got at, this hundreds of years of threat and violence thats been carried out in israel and toward jewish populations. I wonder what your thoughts are about the conversation in this country moving forward about antisemitism. I think the first thing we should do, nicolle, is exactly talk about it the way you just did, that it is real. Its not some fanciful notion. Antisemitism is rising around the world. And then certainly were not immune to that. Its happening here in the United States. I think we need to have an honest conversation. We need to admit that. Unless you if you cant admit that, then you cant do anything about solving it. So weve got to face the facts. Its a brutal truth. Its ugly, and its uncomfortable. I get that. Its a tough conversation to have. But we need to start having it with one another. You heard the president today talk about how were concerned about some antisemitic individuals or groups trying to take advantage of this situation to visit violence on the Jewish Community here at home. And thats why were working with local and state authorities. Obviously, weve got the Intel Community primed and set to try to identify and be able to disrupt any potential antisemitic attacks. We dont want the jewish people, who are already in this country im sure feeling anxious about all this and fearful for their friends, for their families, for israel as a state to not be able to feel like they can live in peace and security, that they wont be able to go to worship, that they wont be able to go visit their family and friends here in the states or go to community centers. We want them to feel safe. The president takes that very seriously, and thats why he addressed it so plainly and so openly in his remarks today. I want to Say Something else about going about the very intense things that you have to do to do your job. The first time you made me cry on tv is the day after bucha was really revealed for what it was, the slaughter of civilians in that town in ukraine. And there is a piece of our desire to survive that we look away. And the evidence of the brutality of this Terrorist Attack is all over, right. Its all over our phones, and there is a real, to protect ourselves a real desire to look away. I wonder what your thoughts are about how much people need to see and understand. You know, thats a personal question. Everybody is going to have to i think figure out for themselves what their tolerance is for the brutal, ugly images that are coming out and the stories now that are being told. Theyre tough to listen to, as well as the images are tough to see. Everybody is going have to make that decision for themselves. I can only speak for me and well, i speak for the government too, but in this case, speaking for me, i felt it was important for me to look at those images, to see them, to better understand for myself the brutality and the barbarity of these terrorists, and it was hard. Obviously its hard. But in my job and for what try to do, i think i need to be exposed to the facts. I need to see the evidence. I need to know whats happening out there, otherwise i cant talk about it. As hard as it was to look at those images, its gutwrenching. I mean, its a gut punch. It really is. And you cant unsee them, which is why i asked for some counsel. John kirby, were lucky to get to talk to you. Thank you very much for your time and for starting us off today. Thank you. Thank you, nicolle. Msnbc National Senior security analyst john brennan is here. Ive wanted to talk to you since this first started happening. I mean, can you take me inside your reflection as sort of the morning, saturday morning revealed the monstrosity of what was happening, was still happening when we woke up saturday. Well, nicolle, ever since saturday morning, weve gotten more and more reports about just how horrific these attacks were. And ive been involved in counterterrorism for the better part of 40 years, and i must say, this is the most horrific series of attacks that ive ever had the had to witness or to talk about. Unspeakable, Unadulterated Evil as President Biden said. What they did to babies, murdered them. Elderly, women, children, i cant get over it. Its sickening, absolutely sickening. And this was purposed by hamas. This is not the hamas of ten years ago. As its been said, this is isis again. This is even going beyond isis. These are fanatical terrorists. And thats why i fully understand why the Israeli Government wants to crush this organization, this organizations ability to continue to carry out these Terrorist Attacks and warmaking. And they continue to rain down rockets on ashkelon. So therefore, its im left speechless. I cant find the words to describe the horror and what these families must be going through who still dont know the fate of their loved ones, whether they are killed and just not yet identified or held captive in gaza. Hamas now has changed the course of history in the middle east. And they are going to rain down all hell, including on the Palestinian People, the innocent palestinians in gaza. And i think it has to be very clear, Everybody Needs to condemn these attacks. And the strongest unequivocal terms. Im waiting for the leaders of arab states to come out and denounce it. This brutality, this barbarism, i has no place in civil society. And that is the time i think for everybody to speak out in support of israel. And there is some real tough choices that the Israeli Government has right now in terms of how theyre going handle this situation. And there is really no good choices ahead. But its something that i believe they need to swiftly and comprehensively, again, destroy the warmaking Terrorist Capabilities of hamas as quickly as they can. I wanted to see if i can press you a little further on something you just said. This is not the hamas of ten years ago. How has hamas changed . Well, hamas is the Governing Authority in gaza. And hamas is a large organization. You know, its a social welfare organization. It handles health care and education. It runs it. But there is this militant now very fanatical terrorist custom brigades that have been responsible in carrying out terrorism. Clearly it has grown in size and influence and it now is dominating