The second geopolitical implication of the current crisis is that the days when the dollar was the sole international reserve currency are coming to an end. Reserve currencies do not last forever, as the case of the British pound makes clear. Once upon a time, sterling was the world’s number one currency, the unit of account in which most financial transactions were done. It died a slow, long, lingering death, sliding from $4.86 in 1930 to very nearly parity with the dollar at the nadir in the early 1980s. “When exactly did sterling stop being the world's number one currency?” is an interesting question. Some historians would say it was as early as 1915, which was the first time that the British government had to issue dollar-denominated debt in New York. Others would say it was in 1931, when the pound went off gold. It certainly was clear by the 1950s that the pound could no longer be the financial anchor it had been in the previous century. The principal reason for that was debt: the huge debts that Britain had run up to fight the world wars. The second reason was lower growth. Britain's economy was the under-performer of the developed world in the postwar decades, right down to the early 1980s.

History’s lesson is clear: the combination of high indebtedness and low growth is lethal to reserve currency status, provided there is an alternative. The last time the dollar weakened significantly, there was no alternative. There is an alternative now. It is perfectly plausible to imagine a world economy in which the euro is at least equivalent to, if not superior to, the dollar. Already, statistics produced by the Bank for International Settlements show that more bonds are issued in euros than in dollars.

A third geopolitical consequence of the crisis we are living through is that troublemakers get richer. The effect on gross domestic product of an increase in the price of oil from $50 to $100 a barrel was a 16 per cent gain for Russia, a 24 per cent gain for Iran and a 33 per cent gain for Venezuela. High energy prices would not matter if there were more Norways or Canadas among the energy exporters, or if significant new sources of energy could be found in the United States itself. But this is not going to happen any time soon, even if restrictions on exploration and drilling in the US are lifted. The biggest increases in oil production in recent years have been in countries like Azerbaijan and Angola.

As those names suggest, a striking feature of the current chase for commodities is that it is taking the commodity importers to ever more exotic locations. A hundred years ago, of course, the scramble for Africa had more or less reached its climax. But back then, many empires were scrambling for African resources. Now there is only one. China's scramble for resources in Africa is one of the most extraordinary phenomena of our times. It is almost as if we are witnessing the genesis of a new empire. And it is happening in the traditional way.

You decide you want resources from a certain place. You feel uneasy about simply relying on market forces to get those resources. So you say “we'll own the infrastructure”. You start to build the roads, the port facilities, to upgrade the mines. And then you discover something awkward about the countries in question: they are politically unstable, particularly at a time of high food prices. So what do you do? “Well, we have to secure our assets. We’d better have a few people with guns there.” Gradually the number of armed Chinese in the vicinity of Chinese assets in Africa increases.