Galicia:
Russia and Austria often bounce each other's armies here in Spring '01.
Turkey should never automatically consider them to be at war if
this happens; occasionally they are, but just as often they've planned
the bounce intentionally to fool the Sultan (and their other foes).
Since Turkey is (usually) the deadliest enemy of both Austria and Russia,
they have a common interest in disposing of Turkey first (immediately
followed by their erstwhile ally here, of course).
By emphasizing seemingly hostile yet ineffective gestures such as the Galicia bounce, they can create an apparent AR war, then both ask for Turkey's help. If the Sultan falls for the ploy, they pounce, revealing the AR alliance. The result: Roast Turkey. :(
Whether you're Austria or Russia, move an army in there or you will regret it when the other does. Galicia borders two Austrian home centers and a Russian one, as well as Ukraine, and a foreign army there wreaks havoc on the Russian position. The question becomes whether or not to reveal your intentions, and this varies from game to game depending on your competition.