Surpluses are not required for the interest obligations either. They're part of the accumulated debt and are extinguished when the associated bonds and financial securities are redeemed. The Federal Government does not borrow from overseas sources. All bonds are issued in sovereign currency.
Evatt Foundation 10/3/11
'A budgetary deficit can be funded by the sale of Govt Bonds,in which case the Govt commits to pay interest to the
holders off those bonds and to repay the principal at future date.The purchasers of the bonds may be Australian or foreign, and only in the latter case does Govt have any relation to foreign debt(and in practice Corporate Debt),usually comprise most of foreign debt.
On one hand Govt debt like your personal debt can be good from the economic standpoint, if it facilitates expansion of capabilities and choices.
On the other hand ,Govt debt like personal debt can be bad if it creates a major burden of interest payments that reduces the amount of tax revenues that the Govt can spend on socially and ENVIRONMENTALLY friendly worthwhile projects.Such debt impedes economic development and increases economic dependency.
Federal debt is not a problem, however (and this is my point) what the debt is used for has to be kept under critical scrutiny."
Thus it still amazes me why Wayne Swan predicted surpluses swell in advance.I'll say it again whilst tax revenues come in based on forward estimates fine,.but if the GFC comes in again in bigger fashion and tax revenues drop substantially particularly when Corporate profits take a dive and unemployment up largely, you already have a big deficit then then Got has to stimulate the economy with further money via debt.
It's one hell of a balancing act, and it affects everyone .