Excerpts from US President Barack Obama's speech, in which he outlines the conclusions of a review of the intelligence failures uncovered by the White House inquiry into the attempted airliner bombing on 25 December.
It's now clear that shortcomings occurred in three broad and compounding ways.
First, although our intelligence community had learned a great deal about the al-Qaeda affiliate in Yemen, called al-Qaeda in the Arabian Peninsula, that we knew that they sought to strike the United States and that they were recruiting operatives to do so, the intelligence community did not aggressively follow up on and prioritise particular streams of intelligence related to a possible attack against the homeland.
Second, this contributed to a larger failure of analysis, a failure to connect the dots of intelligence that existed across our intelligence community and which together could have revealed that Abdulmutallab was planning an attack.
Third, this in turn fed into shortcomings in the watch-listing system which resulted in this person not being placed on the no-fly list, thereby allowing him to board that plane in Amsterdam for Detroit.
In sum, the U.S. government had the information scattered throughout the system to potentially uncover this plot and disrupt the attack. Rather than a failure to collect or share intelligence, this was a failure to connect and understand the intelligence that we already had.
I'm directing a series of additional corrective steps across multiple agencies.
First, I'm directing that our intelligence community immediately begin assigning specific responsibility for investigating all leads on high-priority threats so that these leads are pursued and acted upon aggressively not just most of the time, but all of the time.
Second, I'm directing that intelligence reports, especially those involving potential threats to the United States, be distributed more rapidly and more widely. We can't sit on information that could protect the American people.
Third, I'm directing that we strengthen the analytical process... how our analysts process and integrate the intelligence that they receive.
And, finally, I'm ordering an immediate effort to strengthen the criteria used to add individuals to our terrorist watch lists, especially the no-fly list. We must do better in keeping dangerous people off airplanes, while still facilitating air travel.
Even the best intelligence can't identify in advance every individual who would do us harm. So we need the security at our airports, ports, and borders and through our partnerships with other nations to prevent terrorists from entering America.
Even before the Christmas attack, we increased investments in homeland security and aviation security.
This includes an additional $1bn in new systems and technologies that we need to protect our airports, more baggage screening, more passenger screening, and more advanced explosive detection capabilities, including those that can improve our ability to detect the kind of explosive used on Christmas.
Today, I am directing that the Department of Homeland Security take additional steps, including strengthening our international partnerships to improve aviation screening and security around the world, greater use of the advanced explosive detection technologies that we already have, including imaging technology, and working aggressively in co-operation with the Department of Energy and our national labs to develop and deploy the next generation of screening technologies.
As we develop new screening technologies and procedures, our adversaries will seek new ways to evade them, as was shown by the Christmas attack. In the never-ending race to protect our country, we have to stay one step ahead of a nimble adversary.
'BUCK STOPS WITH ME'
I have repeatedly made it clear in public with the American people and in private with my national security team that I will hold my staff, our agencies and the people in them accountable when they fail to perform their responsibilities at the highest levels.
At this stage in the review process it appears that this incident was not the fault of a single individual or organisation, but rather a systemic failure across organisations and agencies.
That's why, in addition to the corrective efforts that I've ordered, I've directed agency heads to establish internal accountability reviews and directed my national security staff to monitor their efforts.
All of these agencies and their leaders are responsible for implementing these reforms, and all will be held accountable if they don't.
Moreover, I am less interested in passing out blame than I am in learning from and correcting these mistakes to make us safer, for ultimately the buck stops with me. As president, I have a solemn responsibility to protect our nation and our people, and when the system fails, it is my responsibility.
NO 'SIEGE MENTALITY'
We are at war. We are at war against al-Qaeda, a far-reaching network of violence and hatred that attacked us on 9/11, that killed nearly 3,000 innocent people, and that is plotting to strike us again. And we will do whatever it takes to defeat them.
And we've made progress. Al-Qaeda's leadership is hunkered down. We have worked closely with partners, including Yemen, to inflict major blows against al-Qaida leaders. And we have disrupted plots at home and abroad and saved American lives.
And we know that the vast majority of Muslims reject al-Qaeda. But it is clear that al-Qaeda increasingly seeks to recruit individuals without known terrorist affiliations, not just in the Middle East but in Africa and other places, to do their bidding.
That's why I've directed my national security team to develop a strategy that addresses the unique challenges posed by lone recruits. And that's why we must communicate clearly to Muslims around the world that al-Qaeda offers nothing except a bankrupt vision of misery and death, including the murder of fellow Muslims, while the United States stands with those who seek justice and progress.
To advance that progress we've sought new beginnings with Muslim communities around the world, one in which we engage on the basis of mutual interest and mutual respect and work together to fulfil the aspirations that all people share - to get an education, to work with dignity, to live in peace and security.
That's what America believes in. That's the vision that is far more powerful than the hatred of these violent extremists.
Here at home, we will strengthen our defences, but we will not succumb to a siege mentality that sacrifices the open society and liberties and values that we cherish as Americans, because great and proud nations don't hunker down and hide behind walls of suspicion and mistrust. That is exactly what our adversaries want. And so long as I am president, we will never hand them that victory.
We will define the character of our country, not some band of small men intent on killing innocent men, women and children.