by selwyth
Diplomacy allows you to potentially grab an extra area using the Supremacy bonus of Mobilize, though it's rare that I've needed it (makes you a target and spreads you thin).It's also needed when you have one of those crappy Good objectives that force you to ally with neutrals. I hate getting one of those and hope Prepare for the Coming Year comes up soon so I can exchange it.
Both the expansion and Revised Ed have also made neutrals laughably weak to steamroll, thanks to more powerful Heroes. Especially those singleton Dragon and Giant areas.