New York University Professor Nouriel Roubini – famous for having predicted the GFC in 2006 – again defies the so-called ‘conventional wisdom’ by warning that it is the “risky rich” countries who are in greatest danger of sovereign debt default:
Today’s swollen fiscal deficits and public debt are fueling concerns about sovereign risk in many advanced economies. Traditionally, sovereign risk has been concentrated in emerging-market economies. After all, in the last decade or so, Russia, Argentina, and Ecuador defaulted on their public debts, while Pakistan, Ukraine, and Uruguay coercively restructured their public debt under the threat of default.
But, in large part – and with a few exceptions in Central and Eastern Europe – emerging-market economies improved their fiscal performance by reducing overall deficits, running large primary surpluses, lowering their stock of public debt-to-GDP ratios, and reducing the currency and maturity mismatches in their public debt. As a result, sovereign risk today is a greater problem in advanced economies than in most emerging-market economies.
Barnaby Is Right 
If you want a real debate:
Please consider arguments presented by prof Bill Mitchell on his website http://bilbo.economicoutlook.net/blog/
He has directly answered some questions raised by Barnaby in this blog:
http://bilbo.economicoutlook.net/blog/?p=7864
In his view a sovereign country like Australia cannot default on its own debt (in the domestic currency) in the fiat money era.
It appears you have not read the links already posted on this blog – plenty of economic luminaries broadly agree with Barnaby’s concerns. Moreover, like many you have clearly not listened carefully to what Barnaby has actually said… even though the economist at your links quoted Barnaby verbatim:
Barnaby has never said Australia could “default”. The MSM’s edited sound bites and blatantly misleading commentary would have you believe so. But he did not. What he has said is simply logical and obvious – that if we continue on the current trajectory of rising debt, we will reach a point where we cannot pay it back. Big difference.
Any thinking and studious observer knows that it is uncommon for sovereign nations to outright “default” in the traditional sense. Rather, they more commonly devalue their currency (ie, high inflation), or, get loans from the IMF et al, with painful austerity measures as conditions. In less than 24 hours I’ve already found and posted links to a veritable heap of authoritative international economists who concur. Including some who actually have some real-world credibility, since they predicted the GFC.
Barnaby is right to warn of the dangers.
* I note (FWIW) from the anti-right perjoratives liberally used by the academic you’ve linked too, that he is clearly far from an impartial observer. Did he predict the GFC?