If the interest rates of the bonds are too low, they won't sell. If the rates are too high, even the principal might not be secured, making them even less desirable.
Everyone now longs for the good old days when the Moxi people were peddling war bonds. High returns were guaranteed, and their repayment capacity was secure. Direct taxes were imposed for repayment, forcefully apportioned among the nobles within the country.
Such a method, however, is not feasible in the Alpha Kingdom.
The Moxi people could withstand this as they were at the brink of total ruin, and rejection would have meant complete destruction. Even if it harmed their own interests, the nobles had no choice but to accept it begrudgingly.
Now, in the age of the counteroffensive, even if the Alpha Kingdom's nobility has to end the war prematurely due to a lack of funds, they can accept it.
In such a context, you'd better not even think about exploiting them and bleeding them dry in the long term.
