This suggests some form of conflict, internal or otherwise. The army might be depicting the forces or qualities you muster to deal with difficulties – i.e. courage, information, aggression or anger. It might be attitudes necessary to face anxieties.
The army is also an organisation and the dream might be about how you are relating to being organised, being told what to do, being under orders, or working within an organisation amongst many others. So it is important to recognise how you feel in the dream. Do you feel trapped, part of something, alone in a crowd, or a meaningful part of something bigger than you?
Sometimes army dreams occur when you are ready to confront the internal traumas and conflicts you carry. The important aspects of such dreams are about what they show of your attitudes or feelings about the army. See: soldier; war.
What are my feelings about the army, or being in the army?
Is this army fighting for something, if so, what? How does that link with myself?
Am I avoiding or being part of the group?