ORIGINAL: Kaliber
But there are additional problems for the CP: if the TE opens up a land route over the Balkans, they can not only ship resources to Russia, but it also puts AH in a very delicate situation. In short, whereas Russia can rail back and forth across the Balkans, AH effectively has the choice whether to deploy units to the south (in my ongoing game the russians are advancing on Budapest from Serbia/Romania) or to ship resources to Germany. The russians could very well embark on a rail back and forth strategy to keep the precious AH rps busy.
First: I'm not sure if this wasn't always the case and is 1.30f specific.
Second: I cannot rail back and forth across the Balkans. Once in Romania/Serbia the Russian troops use those countries rail points and there a few of them. Actually the corps advancing towards Budapest were in Romania, then I walked them out of Romania and across the Russian border and then I railed them into AH. I don't think I can rail them back. Its a one way ticket.
Third: Fighting on so many fronts has always kept the CP busy.