Now? Prices everywhere are falling as recession bites. Investment banks have disappeared; and the global credit system is on life-support. The big threat is deflation rather than inflation. The oil price has slumped, wiping the smirk from authoritarian leaders such as Russia's Vladimir Putin and Venezuela's Hugo Chávez.

When Barack Obama won the Democratic nomination for the presidency he expected Iraq and healthcare would be the priorities of his presidency. No one told him the banks were facing bankruptcy and the US an economic shock as severe as any since the Great Crash.

The scale and speed of this turnround offers a stiff warning of the perils of seeking to peer beyond the present. Think back also to all that stuff a few years ago about the unipolar moment and the new American imperium. The mistake always is to project the here-and-now into an indefinite future. History rarely travels in straight lines.