Not sure if serious but it can be any number of things or combination thereof. Most of their operations are so covert that they don't necessarily know who they are fighting. They also don't direct control of their operations all the time, so they do things like give weapons to someone hoping that they do something with those weapons, but they might do other things in addition or instead of what they were supposed to do. Then there's also the fact that these agencies are all fighting with each other for bigger pieces of the budgetary pie.
why would the alphabet organizations fight each other?
Not sure if serious but it can be any number of things or combination thereof. Most of their operations are so covert that they don't necessarily know who they are fighting. They also don't direct control of their operations all the time, so they do things like give weapons to someone hoping that they do something with those weapons, but they might do other things in addition or instead of what they were supposed to do. Then there's also the fact that these agencies are all fighting with each other for bigger pieces of the budgetary pie.