Here's a number to make your day. I suggest sitting by a window so you can read in the daylight. Then stare out at the world and wonder at the depths of human folly. Are you ready for the number? Here it comes. 3,200,000,000,000. Oops, I forgot. There should be a dollar sign in front of that. $3,200,000,000,000. Doesn't that make it easier to read?

Now how about a quiz? No, two quizzes. The first one: how do you say a number like that? My guess is three trillion, two hundred billion. Those other zeros? Millions, hundred thousands and so on? Small change, so we disregard them. Second quiz: what does that figure represent? It wasn't conjured out of thin air, although I wish I had. Here's a hint. Much of what that sum of money buys is bad for you.

Although depending on your point of view, it can also be good for you, especially if you get a piece of the action, some of the spending it represents. Sorry, almost gave the game away. Give up? Well by now, you won't be surprised to know that this number (let's write it again, counting the zeros carefully because I've never typed anything like this before) $3,200,000,000,000 is an official estimate from the US government of defence spending by the Bush administration up to the end of fiscal year 2008. If anyone wants to check, the Office of Management and Budget will be glad to verify.

It's an astounding and unprecedented figure, a lot of bucks for, presumably, a lot of bang. It's the defence budget of a country at war, with terror, with tyranny, with drugs, with various other, admittedly evil forces that so far, show themselves almost impossible to defeat. Anyone seen Osama or Saddam lately?

So far, the US military operation in Iraq, including the occupation of the country, has cost the American taxpayer just under $100 billion with much more to come. In fact, no one can actually say how much more it's going to cost because many expensive items won't appear on the books. They won't even signal that they're coming over the accountant's horizon.

Terrorism, fanaticism and self perceived righteous anger is like that. It comes to town, wreaks havoc and even if it's fended off or devastated, lives to fight another day. And to lay claim to money that you'd rather spend on yourself or your needy neighbours. A lot of people would shrug and say "Well, somebody's got to do it, and what better society than the most free and wealthy among us, the most innovative, creative and generous." America has been prosperous and at peace for a long time, and it's people generated wealth like no others in the world.

Hard work, innovation and refusal to give in to failure are the hallmarks of American civilisation, what the rest of us admire most about the place. All this is true. But never before have such sums of money been involved.

Nor-crucially-have so many of beneficiaries of military spending been large private firms that wage war for profit.

Not the huge mercenary armies, but the legions of private contractors who receive up to one-third of much of modern military spending. Let's see, one-third of all those trillions above is $1,066,666.666,666. Not bad, a cool trillion for the private sector with a few dozens of millions left as spare change, to buy a yacht or two. Pin money they used to call it. Money for old rope. And for commando training, firing range services, runway construction, repairing places (like Iraq) that US bombers have blasted to smithereens, canteen operation, catering to huge occupation forces and just about every other service short of actually fighting and laying down one's life for one's country. In the first Gulf war in 1991, one in one hundred US personnel in the Middle East worked for a private contractor. Now it's one in ten.

Along with that figure up above, get to know these names by heart because they matter: Halliburton, Kellogg, Brown and Root, Bechtel. So far, these are the firms benefiting from the largest chunks of that trillion and change mentioned earlier. Many other companies are too, often run by ex-servicemen and women in what the American media are just beginning to uncover as potential conflicts of interest. You can worry, or you can get on the gravy train. Because it's coming around the bend. And it's unstoppable.