The starting point for energy security today as it has always been is diversification of supplies and sources.

In a world of increasing interdependence, energy security will depend much on how countries manage their relations with one another. That is why energy security will be one of the main challenges of foreign policy in the years ahead. Oil and gas have always been political commodities.

Cycles of shortage and surplus characterize the entire history of oil.

The North Sea was supposed to run out in the 1980s. Then in the 1990s. And now production is still on-line.

But the key thing is that Iraq, while it's got very large oil reserves, has marginalized itself as an oil exporter and these days its exports are only about one tenth that of neighboring Saudi Arabia.

So the major obstacle to the development of new supplies is not geology but what happens above ground: international affairs, politics, investment and technology.

First, we have to find a common vocabulary for energy security. This notion has a radically different meaning for different people. For Americans it is a geopolitical question. For the Europeans right now it is very much focused on the dependence on imported natural gas.