Once Austria gets the OO card, which subsidy reduction causes the OO to fail? Is it only one of the subsidy reductions to Prussia or, rather, does a subsidy reduction to France/Austria also cause the OO to fail?
Here is a follow-up question to Bruce's original question...
After the first subsidy reduction (and Austria has picked up the open TC "ransom"), the OO has failed and Prussia can only win by defense. Can Austria--as per the OO rules--still claim conquest of any 4 objectives at any time (even after the OO has failed)?