Saudi wife business is a cover story. She was brought here to complete the cell. Their baby was just a prop to bones on their image as a “normal” American couple. They were knee-deep in explosives ready to be manufactured into IEDs. Must have been in the planning stage for a year or more. Most likely they had planned to use them to create widespread damage. But when Farook got wind of the office party they changed the plan. A roomful of infidels confined in one place was too good to pass up so they put all their eggs in one basket!
One final word: These people may be crazy, but they're not dumb. They’ve been at it for 1400 years. Look for future attacks in places like San Bernardino. Unexpected and somewhat out of the way. The juicy targets in our big cities are watched too carefully by law enforcement. But a martyr is still a martyr and a dead infidel is a dead infidel wherever he lives.
Buckle up, friends. The ride is far from over.