Perhaps; it depends on whether investors have rules about percentage of foreign holdings (many do). You'd also need to find countries with AAA ratings that still have big enough outstanding debts that the markets are sufficiently liquid even for large transactions. For example, Canada has $550 billion in total outstanding bonds, so you couldn't easily move $50 billion there, since that'd require buying up 10% of the entire market. Even moving $5 billion there is buying up 1%, which the liquidity may or may not support.