If you attack a base you can find a fight, or simply ask on country.
Yup, if I want to fight with a manned gun I could do that.
More often than not defenders may up, but if it doesn't  look like it is a base capture mission, they just move on. A squad in and I took out ammo and deacked a field. One guy upped a couple of times and then left. There was only the 2 of us in the air.
Meanwhile,  the 49ers were running their gv mission and rolled in with a dozen vehicles.  They took the town out and captured the  base while my squadie  and I just cooked through our fuel waiting for a defence.
Yup, another great fight.