(the) Security forces helped us fight (the) terrorists.
If I wanted to refer all security forces in a specific country would I need to use a definite article? Same with "the terrorists", I want to make clear that the security forces are fighting not all terrorists but a few groups of terrorists; would I have to use the definite article then?
The question this is supposed to be a duplicate of talks about generic noun phrases. This means things that do not actually exist in the world (you can't feed or take a photo of a generic lion, for instance). I am talking about noun phrases (security forces, terrorists) that actually exist and fight and die in a specific country. We can feed and and photograph them. They are "real," not generic.
The Security forces helped us fight the terrorists
can imply that one group of security forces helped fight one group of terrorists, that several groups of security forces helped fight several groups of terrorists, or any combination of those meanings. If you wanted to clarify, you'd have to use quantifiers like "all", "some", "several", "one", etc. "All the Security forces in the USA helped us fight several terrorist groups."