US President Barack Obama said Thursday security lapses that led to a near-disaster in the Christmas Day attack on a US-bound airliner were not the fault of a single individual or agency and suggested no one would be fired. He vowed the problems would be corrected. Obama did not tell intelligence officials to dramatically change what they are doing. Instead, he told them to do it better, and faster. He left it to them to figure out how. Clearly aware of the potential political fallout, Obama struck a tough tone toward the anti-terror fight, taking the rare step - for him - of calling it a "war." In one concrete change, the administration is adding more air marshals to flights. Hundreds of law enforcement officers from Homeland Security Department agencies are being trained and deployed to the federal Air Marshal Service, said a government official familiar with the strategy. There are more than 4,000 federal air marshals but many times that number for domestic and international flights each day. In the president's bleak assessment and a White House-released report about what went wrong, the US got an alarming picture of a post-Sept. 11 debacle: an intelligence community that failed to understand what it had. US intelligence officials had enough information to identify the suspect as an al-Qaida terrorist operative and keep him off a plane but still could not identify and disrupt the plot, and security measures didn't catch him, either. Obama announced about a dozen changes designed to fix that, including new terror watch list guidelines, wider and quicker distribution of intelligence reports, stronger analysis of those reports, international partnerships and an interagency effort to develop next-generation airport screening technologies. More inquiries are on the way. "It is appalling that we have not learned from our mistakes, eight years after the worst terror attacks in our nation's history," said Sen. Olympia Snow, a Republican member of the Senate Intelligence Committee, which will hold its first hearing on the subject on Jan. 21, probably in private. While Obama promised improved security, his solutions were laced with bureaucratic reshuffling. Americans might be surprised that the government was not already taking some of the steps Obama ordered. For instance, he directed the intelligence community to begin assigning direct responsibility for following up leads on high-priority threats. Obama himself hinted at the difficulties of improving intelligence and security against a terrorist network that devises new methods as fast or faster than the US can come up with defenses. "There is, of course, no foolproof solution," he said. "We have to stay one step ahead of a nimble adversary." He spoke from the White House, his remarks delayed twice as officials scrambled to declassify a six-page summary of a report he had ordered from top officials on the security failures. That summary was released immediately after he spoke, as was Obama's three-page directive to agency chiefs. "When the system fails, it is my responsibility," Obama said. The White House is anxious to resolve and move beyond the issue, which threatens to damage the president politically and distract further from his agenda. Republicans have pointed to the attack and Obama's handling of it to criticize him as weak on national security - a perennial election-season charge against Democrats that has sometimes been effective in the past. His language Thursday was strong. "We are at war, we are at war against al-Qaida," he said. "We will do whatever it takes to defeat them." The unclassified summary stated that US intelligence officials had received unspecified "discrete pieces of intelligence" to identify Umar Farouk Abdulmutallab, a 23-year-old Nigerian, as an al-Qaida operative and keep him off the flight from Amsterdam. Officials received fragments of information as early as October, according to the report. Earlier Thursday, the administration said Abdulmutallab was flagged for extra screening after he was already on the plane and headed for Detroit. The Department of Homeland Security said his potential ties to extremists came up in a routine check of passengers en route to the US - and not because of any suddenly gathered intelligence that emerged during the flight. Although intelligence officials knew that an al-Qaida operative in Yemen posed a threat to US security, they did not increase their focus on that threat and did not pull together fragments of data needed to foil the scheme, said the summary. Still, the report concludes, "The watch listing system is not broken" and a reorganization of the nation's counterterrorism system is not necessary. The report, instead, calls for strengthening the process used to add suspected terrorists to watch lists. According to the report, "a series of human errors" occurred, including a delay in the dissemination of a completed intelligence report and the failure of CIA and counterterrorism officers to search all available databases for information that could have been tied to Abdulmutallab. Unlike the run-up to the 2001 terrorist attacks, intelligence officials did share information. But authorities didn't understand what they had. The president seemed to settle the question of whom to blame by declaring that blame was shared by many. "Now at this stage in the review process, it appears that this incident was not the fault of a single individual or organization, but rather a systemic failure across organizations and agencies," he said. He ordered all involved agency heads to set up internal accountability units to review efforts to make changes. "We will measure progress," he said. Underscoring Obama's assertion that no one individual was responsible for failing to thwart the attack, the administration's report noted that Abdulmutallab's name was misspelled in one instance, leading the State Department to conclude he did not have a valid US visa - when in fact he did. Even so, the report said steps to revoke his visa could have occurred only if other intelligence information had been coordinated and he was placed on a more restrictive watch list. Abdulmutallab was indicted Wednesday on charges of attempted murder and other crimes in the airline incident.