The Bank performs many functions: e.g. intervening in foreign exchange markets as an agent of the Finance Minister, providing services to foreign central banks and international organizations wishing to invest in yen. In addition, the Bank is actively engaged in activities related to international finance through channels other than the BIS, including the G7, G10, IMF, etc.
As a result, they are forcing some countries to pay risk premia that are not fully justified by underlying fundamentals, making those destructive scenarios self-fulfilling. But this aspect of debt sustainability can be addressed by simply changing perceptions. Here, the ECB’s recent announcement of Outright Monetary Transactions should play a supportive role.