Top left hand corner of Washington District..
Wants me to give signal but I have No Allies Available...
Man alive, what have I got to do?
I've already killed the boss and everyone else..
There's only a set amount of "green pistols" walking around the map.
If a friendly CP is under attack you have one less. If your friendlies are attacking a CP you're another one short.
Go help them at either spot or just wait for a little while
Thanks, I sorted it, I went and completed all the other control points I could at the level I'm at and went back to The Vault.
Thanks for the explanation...