What's to stop the Countess from having precommitted to never respond to blackmail?

Or to have precommitted to act as though having precommitted to the course of action having precommitted to in retrospect seems the most beneficial (including meta-precommittments, meta-meta-precommitments, meta^meta^meta precommitments etc up to the highest level she can model)?

Which would presumably include not being blackmailable to agents who would not try to blackmail if she absolutely committed to not be blackmailable, but being blackmailable to agents who would try blackmail even if she absolutely committed to not be blackmailable, except agents who would not have modified themselves into such agents were in not for such exceptions. Or in short: Being blackmailable only to irrationally blackmailing agents who were never deliberately modified into such by anyone.