PLEASE at least cut it down to 6 hours, it makes no difference to "spies" people have second accounts, they will use them...
Most of the time I log in twice twice, i'm stuck whatever country I choose, would be nice to have a 6 hour in case a horde breaks out.
From my point of view: I log on at 2pm - I switch countries depending how things go, I log out an hour later.
If I log back in at 7pm and the country I switched to is hording - either I join the horde or log off since I can't switch to whoever is losing.
Snailman pointed out people don't switch countries just to join the war winner, or join the hordes - most are relatively country "static" leaving just the few dog fighters or those looking for a decent fight to switch.
It has nothing to do with spies either, one squad only needs access to one shade in which people can use, so why ruin the fun for the dozens who switch sides to find fights?