An Army intelligence officer yesterday publicly charged that the unit in which he worked had indeed identified two al Qaeda cells — and 9/11 ringleader Mohamed Atta more than a year before the terrorist attacks. Properly handled, Lt. Col. Anthony Shaffer says, that information might have prevented the terror attacks. And Shaffer insists that his unit, code-named Able Danger, provided that information to the 9/11 commission headed by former Gov. Tom Kean — which failed to include it in its final report. Moreover, the officer's revelations come as newly declassified documents show that State Department analysts warned the Clinton administration...