Documents discovered by Navy SEALs in Osama bin Laden's Abbottabad hideout show that the al-Qaida leader was plotting a second September 11th attack.

Bin Laden and al-Qaida operations head Attiyah Abd al-Rahman were discussing their next terrorist strike on the United States, set for the 10th anniversary of the attack that brought down the Twin Towers in 2001.

The plot was still being worked on and the two talked about recruitment and attack teams. Bin Laden said he was aiming for major U.S. cities like Los Angeles, and considered attacks using trains or planes.

The plan might not have been as terrifying as it sounds, however. Military officials believe that bin Laden's leadership was waning, and he was more of a figurehead than an actual commander by that point.

What we found was that he was very isolated, and it is clearly the case he was struggling to continue to hold on to the type of influence and to direct operations in ways he may have been able to do in the past, a U.S. official told the Wall Street Journal.

He was also in constant disagreement with al-Rahman and consistently rejected the operation chief's suggestions.

The rest of the documents haven't yet provided the government with much useful information.

The treasure trove has not led to any big takedowns, because the bad guys knew we had it and adapted, a senior U.S. official told WSJ.