Dr. Gordon McCormick argues that in the beginning, a small war is symmetric in nature. The state has an overwhelming advanatage in force structure (i.e military/police capability). Conversely, the counter-state(partisan or insurgent force) has the overwhelming information advantage (i.e. the counter-state can see the government, but the government cannot see him).
Initially, these comparative advantages are equal.

The conflict does not become assymetric until one side gains a significant advantage over the other- either the state gains significant intelligence over the insurgent or the insurgent degrades the military/police capability of the state.

Just another way to look at it.

v/r

Mike