The global economy is a runaway train that is slowing, but not quickly enough. That is what the extraordinary run-up in prices for oil, metals, and food is screaming at us. The spectacular and historic global economic boom of the past six years is about to hit a wall.

Unfortunately, no one, certainly not in Asia or the United States, seems willing to bite the bullet and help engineer the necessary coordinated retreat to sustained sub-trend growth, which is necessary so that new commodity supplies and alternatives can catch up.

Instead, governments are clawing to stretch out unsustainable booms, further pushing up commodity prices, and raising the risk of a once-in-a-lifetime economic and financial mess. All this need not end horribly, but policymakers in most regions have to start pressing hard on the brakes, not the accelerator.

Don't look to the US for leadership in a presidential election year. On the contrary, the US government has been handing out tax-rebate checks so that Americans will shop until they drop, and now Congress is talking about doing more.

Don't look to emerging markets, either. Desperate to sustain their political and economic momentum, most have taken a wide variety of steps to prevent their economies from feeling the full brunt of the commodity price hikes. As a result, higher commodity prices are eating into fiscal cushions rather than curtailing demand.

I am puzzled that so many economic pundits seem to think that the solution is for all governments, rich and poor, to pass out even more checks and subsidies so as to keep the boom going. Keynesian stimulus policies might help ease the pain a bit for individual countries acting in isolation. But if every country tries to stimulate consumption at the same time, it won't work.

A general rise in global demand will simply spill over into higher commodity prices, with little helpful effect on consumption. Isn't this obvious? Yes, there is still a financial crisis in the US, but stoking inflation is an incredibly unfair and inefficient way to deal with it.

Some central bankers tell us not to worry, because they will be much more disciplined than central banks were in the 1970s, when the world faced a similar commodity price spike. This time is different, though. The commodity price problem has snuck up on us, despite notable institutional reforms in macroeconomic policymaking all over the world.

The historic influx of new entrants into the global work force, each aspiring to Western consumption standards, is simply pushing global growth past the safety marker on the speed dial. As a result, commodity resource constraints that we once expected to face in the middle of the 21st century are hitting us today.