If you remember, we said that the order B -> A didn't protect A because "any units which could protect A by supporting B -> A could just as easily support A directly." This is true, but what if those other units were foreign, and didn't know that A would be supporting something else? Maybe they think that A is moving somewhere else. It might be possible to trick a country into supporting B -> A even though they wouldn't be willing to support A directly.
Here's an admittedly contrived example. England is about to be attacked by Russia. Russia is going to support himself into the North Sea while cutting any potential support from Edinburgh. England is allied with Germany, but he cannot help. Only France can help protect the North Sea.
The problem is, France doesn't want to help. Not unless England backstabs Germany, that is. France will support Edinburgh to the North Sea (thereby keeping it from Russia) if the North Sea will attack Holland.
England appears to have no choice, so he agrees to go along with France's plan. But Perfidious Albion is subtle as well as treacherous! Knowing the French support will protect the North Sea, he orders the North Sea to support Germany against Russia!
England: Fleet North Sea SUPPORT GERMAN Fleet Kiel -> Denmark.
England: Fleet Edinburgh -> North Sea. (*bounce*)
England: Army Yorkshire -> Edinburgh. (*bounce*)
England: Army Liverpool SUPPORT Army Yorkshire -> Edinburgh.
Russia: Fleet Denmark -> North Sea. (*bounce, dislodged*)
Russia: Fleet Norway SUPPORT Fleet Denmark -> North Sea.
Russia: Fleet Clyde -> Edinburgh. (*bounce*)
Russia: Army Sweden -> Denmark. (*bounce*)
Germany: Fleet Kiel -> Denmark.
Germany: Army Holland -> Belgium. (*bounce*)
France: Army Belgium SUPPORT ENGLISH Fleet North Sea -> Holland. (*void*)
France: Fleet English Channel SUPPORT ENGLISH Fleet Edinburgh -> North Sea.
The point is that while the French fleet could have supported the North Sea to hold, he didn't know that it would be holding. In fact, if he had known that it would be holding, he wouldn't be offering his support at all.
Is anyone still with me? I hope you've had as much fun with Manus's question as I have. I can certainly see why it's his favorite!
