Perhaps to pick up a weapons cashe and explosives from a friendly North Korean sleeper cell living undercover as 'wealthy Chinese emigrants' in Vancouver, a city swarming with over 300,000 Chinese?
Los Angeles would be a likely target for such an attack for several reasons: (1) To prove aQ is capable of rudimntary planning and evading capture (to attract admiring Islamics); (2) To terrorize the U.S. with fear and the impact of targeting both coasts; (3) To maximize publicity of a high profile attack in California.
Possible targets come to mind: The Rose Bowl Parade, the Rose Bowl itself, and the very heart of film industry residing moguls in Pasadena and Beverly Hills.
That would be too good to be true.