The "nation" property on every mobile should be set to the nation of the mobile, unless it is the "default nation" (in the case of Cryosphere this is british)

If the "nation" property is explicitly on a mobile, and it gets into a fight, then every mobile with a "nation" property which is the same, will assist it. Before this happens, the before_joinin trap will be called on the mobile, with o2==the person it would attack. If this trap returns 1, the mobile will not intervene.

Some nations that exist as objects include

american	United States of America
british (default)	United Kingdom
canadian	Canada
centauri	Free State of Centauri
chinese	Federal Republic of China
evil	You are allowed to kill nation Evil mobiles in peaceful zones. Aggressive evil mobiles will also attack non-evil mobiles
predator	Predator mobiles will attack other mobiles.
french	France
indian	Union of India
lamidav	Lamidav
portuguese	Portugal
treeng	Treeng