It's only when you go places that you realise environmental truths.

And this one, as far as I can tell, has nothing much to do with the motor car. But that doesn't make it any the less important.

Then, maybe it HAS something to do with the car, if the car is really as key to global warming as some of its opponents say.

But let's stay with the facts as I found them.

I spent a week in Utah recently, and a couple of conversations I had brought home to me that even the most powerful country in the world can't always help itself against over-consumption of its most important resource.

Such as the time when I was camping beside Lake Powell, a reservoir established by the damming of the Colorado River at Glen Canyon, one arguably as big as the Grand Canyon.

It struck me that the vegetation and coloration of the surrounding rock features indicated that at some recent stage, our campsite had been under water. I notice things like that. I wanted to be a geologist when I left school.

"Yes, the water level is 95 feet lower than it should be, because of drought here over the last three years," a Park Ranger confirmed. "There's not been enough rain to keep the lake full, and there's too much draw off of the water, before and below the lake, because of farming needs and a lot of development. We're hoping that the snow runoff will bring it up 20 feet before the summer, but next year we reckon it will be even lower."

There is a very serious water problem developing in this part of the US, and the stuff may well become more scarce and more contentious than oil in a not-distant future.

It is a situation that was further confirmed by a couple of rangers I met a few days later, upstream near Moab on the Colorado River (above). They'd been checking on the numbers of a particular pike native to that river, but which is now an endangered species because of changes in the river habitat. That day, they'd found none.

"It's no longer the 'mighty Colorado'," one added, and to this observer, it certainly seemed a river as tame as the Shannon back home.

So here is a thought. We have recently observed (some would say participated in) a war that, whatever the official - often changed - reason was really about securing for the US the oil in Iraq.

Not too far away is a large country with plenty of water, but with a relatively tiny population. One which didn't support the US war on Iraq, and which therefore could, under the current US administration's thinking, be considered as a 'supporter of terrorism'.

That country is Canada.

So, what's to stop George W Bush declaring that Canada needs 'a regime change' and invading its relatively puny population on the grounds of US 'national security'?

The water, there for the taking, would be a by-product of the 'war against terrorism'. As is Iraqi oil.

And the problem which is already causing towns and counties in the 'Big Sky Country', which has traditionally fed the water needs of California, Nevada, and upstream Colorado, to die of thirst, would be solved.

One also wonders what line would British prime minister Tony Blair take in such a move against a Commonwealth country? Where would lie the 'special relationship' then?

I'm tempted to write a novel about it.

But it would be incredible, wouldn't it?

Trouble is, several of the stories I've already written have in various ways come true ... like the killing of everybody in a big New York skyscraper (in 1984). Not to mention the SARS scare (in 1998).

Still, who would believe me on this one ...?