Threats of trade protectionism, plus unilateral actions on the exchange-rate front, such as the heavy interventions of China, Japan, and Switzerland in the currency markets - not to mention the retaliatory tariffs recently passed by the U.S. House of Representatives - endanger growth prospects and could further depress financial market confidence.

Our long-term prosperity depends critically on the ability of world leaders to make politically difficult decisions at a time when the global economy is still vulnerable on so many fronts.

It is time to recognise that austerity alone condemns not just Greece but the whole of Europe to the probability of a painful and protracted era of little or no economic growth. This would be a tragedy not just for Greece and for Europe, but for the world.

Greece's unprecedented fiscal effort, which was more than planned, has triggered much larger contractions of economic activity and the tax base than the original program had assumed.

I think it is incumbent on the rest of us - and I would suggest that includes other European leaders - to pause in what has become a very popular game of telling the Greeks how to run their lives.

It was very important for us to hear that both European governments and the IMF are going to sustain and augment their commitment to Greece because they don't pursue the debt reduction route. They're actually extending more debt, more loans to Greece.