I envision a scenario where a government, or some other entity, creating armies and sending them into the field. Some event or situation comes up, and the government is now completely bereft of any capacity to provide for the armies in the ways that governments do: materiel, intelligence, coordination, or even orders.
The government's solution - not to disband the units - but in a final communique to order the armies to provide for themselves. These armies are still armies, but they have no top-level management. They are conceptually "orphaned" or - something.
One might say "the (army|division|unit) was ____" or "When the _____ occurred" "when we had the ____".
Your suggestions are appreciated.