It happened once way back in 1979. Even then the US lawmakers dilly dallied before raising the debt ceiling. But things are very different now. And the unthinkable 'debt default' by the US in 2013 could have far bigger repercussion than 3 decades back. For one, there is far greater foreign ownership of US Treasury bills. China can vouch for that. Secondly, the US economy is far more vulnerable to recession. This makes the risk of a creditor exodus more real and is damaging prospect for global economy. Most importantly, the US is carrying a much larger debt burden today than it ever did. It is struggling to refinance more than US$ 4.6 trillion worth of debt that becomes due for repayment within two years. Thus envisaging a debt default by the US is not as easy as it sounds in academic terms. A default of such proportion could trigger a wider paralysis in the global financial system. Hence for this to materialize, investors need to be prepared for a financial crisis lik e the one seen in 2008.