What did US intelligence know before the 9/11 attacks?

Twenty-five years after the September 11 attacks, the CIA has released a series of presidential briefing documents showing what United States leaders had been told about Osama bin Laden and al-Qaeda in the years before the plane hijackings that killed nearly 3,000 people. CIA Director John Ratcliffe called the release of the documents “an act of exceptional transparency”. This is the agency’s largest-ever release of presidential daily briefs, the classified intelligence summaries written for the president and his most senior officials.