It was generally agreed, I believe, that such a “nuclear weapon” would only be used when there was a fundamental disagreement between the Governor and the Minister, and that following its use, the Governor would resign. In this way, the rights of a democratically elected government to determine policy were balanced against the needs of the Bank for operational independence.
To maintain confidence in the government, achieving the medium- to long-term fiscal balance is an important precondition. Support by the public is also essential in achieving the fiscal balance. Confidence in government securities is  5  Fukai, Eigo, Reflections on Seventy Years, 1941 (in Japanese).