In the two and a half months between the election and this week’s inauguration of President Barack Obama, America’s public policy debate has been focused on prospective budget deficits and what can be done to reduce them.

The concerns are partly economic – there is a recognition that debts cannot be allowed to grow indefinitely faster than incomes and the capacity to repay them. Then there is a moral dimension in terms of not unduly burdening our children. There is also the global and security dimension, with the concern that the excessive build-up of debt would leave the US vulnerable to foreign creditors and without the flexibility to respond to international emergencies.

Economic forecasts are, of course, uncertain. Yet there is a great likelihood that, in the next 15 years, debts will rise relative to incomes in an unsustainable way if no action is taken beyond the 2011 budget deal and the end-of-year agreement to prevent the nation tumbling over the “fiscal cliff”. So even without the risk of self-inflicted catastrophes – failure to meet debt obligations or government shutdown – it is entirely appropriate to focus on reducing prospective deficits.