If you are talking about the PATS system (Passive Anti Theft System) you can not turn it off or disable it in any way. However, if the theft light is not flashing fast when you are attempting to start the car, that is not the problem.
What is probably the problem is low or no fuel pressure. This is caused by a fuel pump that has reached the end of its life cycle. The only to know for certain is to do a fuel pressure test at the engine. You need 30 psi at the fuel rail for the vehicle to run correctly.
Just disconnecting the battery does not reset the PATS system.
It does reset the engine computer.
But I think that you had a conincedence only.
When you said no, does that mean that the theft light is not flashing fast when you are trying to start the car?