The CIA headquarters in Virginia. Former officers have accused the service of institutional weakness. Photograph: Larry Downing/Corbis/Sygma

Long-term weaknesses in US intelligence-gathering have been ruthlessly exposed over the last fortnight by the Christmas Day airline plot and the Afghanistan suicide bombing which killed seven CIA officers, according to former and serving intelligence officers.

Barack Obama joined the criticism yesterday, slamming the agencies for a near-catastrophic intelligence breakdown over the 25 December bomb attempt.

Speaking after a White House inquest to which he called all the agencies involved, he expressed frustration and anger at the way the bomb plot had been handled: "The system has failed in a potentially ­disastrous way." In a departure from his normally cool public demeanour, the president said that the intelligence services had had all the information they needed about the plot and the Nigerian suspect Umar Farouk Abdulmutallab, but they failed to connect the dots .

"I will not accept that," he said. "We have to do better. We will do better and we have to do it quickly. American lives are on the line."

White House officials said later that no one had offered to resign at the meeting. However, it could prove harder to avoid either sackings or resignations when the outcome of a review into the intelligence handling is published later this week.

Former and serving officers are scathing about the way the operation in Afghanistan has been run and see it is part of an institutional weakness in the CIA and other intelligence-gathering agencies.

They said that the biggest US crisis in intelligence-gathering since 9/11 had been brought about mainly because no single agency is in charge, with a dozen agencies fighting for their own turf.

One of the most damning assessments came from a serving officer, Major General Michael Flynn, deputy head of military intelligence in Afghanistan. In a lengthy report published on Monday evening for a Washington thinktank, he and colleagues said the vast apparatus in Afghanistan was only marginally relevant. Analysts in Washington were so starved of information that "many say their jobs feel more like fortune-telling than detective work", the report says.

In an interview with the Guardian, Larry Johnson, a former CIA officer and counterterrorism agent, said it had become "sloppy" in its field intelligence gathering; the suicide bombing at Khost in Afghanistan which killed eight, including the seven CIA officers, was part of that.

The CIA thought it had turned Humam Khalil Abu Mulal al-Balawi, a Jordanian doctor, into one of their agents. It allowed him onto the base after he asked for a meeting, offering as bait a promise of information about the whereabouts of Osama bin Laden's deputy, Ayman al-Zawahiri. He then blew himself up.

A school friend, Mohammed Yousef, said that Balawi had deceived his ­family and friends in Jordan, telling them in March he was going to Turkey for studies when he in fact travelled to Afghanistan to join militants. He had wanted to die in a holy war, and wrote angry articles on the web calling for jihad against the US and Israel.

Johnson pointed to failures at Forward Operating Base Chapman in Afghanistan, where the attack was made: a source supposedly as significant as Balawi should never have been brought inside the base, because it risked exposing him; also, he should have been debriefed by a much smaller group, not the dozen or so CIA men present when he set off the bomb.

He described those errors as symptomatic of a larger trend within the agency. "You have a lot of inexperienced people being shoved out into the field without adequate mentoring and without proper training," Johnson said.

The CIA has had many crises since its inception in 1946. A high point was its claim to have helped win the cold war, but a low point was reached with the failure to prevent 9/11. Last year the Obama administration revealed details of waterboarding and other torture, and there were reports of links with the private contractor Blackwater, being sued by Iraq for killing civilians in an unprovoked attack in 2007.

Pat Lang, a veteran former head of analysis and clandestine human intelligence for the Defence Intelligence Agency, echoed Johnson's criticism of the Khost operation. "A number of basic rules were violated. One that comes to mind is you never trust foreign agent assets," he said.

"I think it is a very big crisis. It shows that the level of skill in operations has declined so far that they [the CIA] are a menace to themselves," said Lang.

According to Lang, one major flaw was the failure of the Bush administration after 9/11 to put one agency in overall charge.

Gary Berntsen, a former senior CIA officer in the Middle East, said a hiring freeze under President Bill Clinton had left a gap at the CIA. "When a bunch of guys like me retired all at 50, there's a gap. And now we've got a lot of inexperienced people coming on who are being forced into senior positions in the field before they're ready."

But he disputed suggestions that the bomb at Khost indicated systemic problems. "The agency deals with these sorts of things every single day successfully; this is an individual case where they failed. They got beat on this case, they got beat bad … My heart goes out to the families. But this does not indicate the agency is in crisis in any way."

He also criticised Obama's selection of Leon Panetta to head the CIA, noting his lack of intelligence experience. "I'm sure he's learning every day, but you don't need to be learning on the job. For anyone to say it doesn't have an effect is dishonest."

Obama promised within days of his inauguration last year to close Guantánamo in Cuba within a year. The timetable has slipped and he has been accused by right-wing critics of endangering American lives.

But yesterday, after the White House meeting, he shrugged aside the critics and said he would continue with a plan for closure of Guantánamo Bay, a detention camp which had acted as a recruiting base for al-Qaida. He added, though, that he was suspending the release of Yemenis on security grounds.