They will take up global responsibilities, or choose to live in isolation from the challenges of our time.

Climate change is the defining environmental challenge of our time.

"This is the practical and moral challenge of our time."

"Helping the Russian people to build a free society and a market economy - this is the greatest strategic challenge of our time," he said.

Do such events not suggest that this is the most important challenge of our time?

The nation state is no longer the appropriate context in which to deal with many of the great challenges of our time.

It is about our response to the economic, social and environmental challenges of our time.

Eradicating poverty is the most pressing global challenge of our time.

The challenges of our time cannot be tackled if we keep to the old methods.

It is our responsibility to find the right response to the challenges of our time and to do this at the most appropriate moment.