And "boondoggle" is an American word. It means an "unnecessary undertaking", such as paying people to dig holes then fill them in again.

Maybe we could use "boondoggle" a bit more in Australia, especially when the government says it will spend more of the defence budget on making weapons locally and therefore at great expense.

The latest such instance is the seemingly exciting project to set up missile manufacturing in this country. It sounds like an unarguably good thing but, in fact, it is more likely to be a waste of defence funding.

We already have costly naval shipbuilding programs in South Australia, the state of so many marginal seats, and uneconomical manufacturing of army vehicles and much other equipment elsewhere.

Australians need the defence budget to keep them safe amid a rising threat from China. Not a penny should be wasted, and certainly not on what often has an odour of vote-buying by a government eager to announce that it's creating jobs.

The Department of Defence kicked off the missile project, grandly named the Sovereign Guided Weapons Enterprise, earlier this week, requesting information from companies that could contribute. Scott Morrison had announced the plan in March. It's going to cost $1 billion to set up, before we pay for what will surely be expensive missiles.

According to Defence Minister Peter Dutton, we're getting "a sovereign capability to manufacture a suite of precision weapons".

For decades, warships and aircraft have relied almost completely on missiles to shoot at other warships and aircraft. As air defence systems get stronger, aircraft increasingly need to fire missiles at ground targets - from a distance, because they can't get close enough to drop bombs.

Armies these days expect to fire fewer shells and mortar bombs, but more missiles.

The superficial reasoning for making missiles here is persuasive enough: if Australia went to war, it would need lots of missiles, which it might not be able to buy in a hurry from foreign suppliers. So it seems we had better be able to make such weapons ourselves.

But it only takes a moment's thought to realise that there must be something wrong there. If we haven't been making our missiles until now, wouldn't that mean we haven't been able to defend ourselves? And does every other country make its own missiles?

Indeed only a few do, and those that do generally make only some of the missiles they need.

So there must be another way to do it - and it is, of course, buying stocks of as many missiles as we estimate we would need, plus a good deal more just to make sure. Stockpiling has been Australia's main approach since we first began acquiring guided weapons soon after World War II.

In fact, we have usually not had big enough stocks of any particular type of missile, and we certainly do not now. So we should buy more.

The cheaper they are, the more we can buy. They're cheaper if they come from a busy foreign production line that feeds its large local customer, such as the US military, and the global market. So there's the attractive alternative to local manufacturing.

But what if we discovered in an emergency that we needed even more than we had carefully stockpiled? Wouldn't we need to make our own missiles then, regardless of the cost?

We'd certainly like to, but the other side of this story is that we just won't be able to.

We use many types of missiles and would probably need all types in a war. To be independent of foreign supply, we would have to have a local production line for each type, each of which would be dribbled out at some tiny, uneconomical rate, corresponding to the modest demand of our modestly sized armed forces.

To improve the economics, we could choose just a few types to manufacture and hope exports would keep the factories moderately busy. In fact, the government is probably aiming for something approaching that, though it's hard to see how costly production here could compete in the export market.

MORE AGE OF THE DRAGON:

But if we make only some of the missiles we need, we'll still need to stockpile the others and rely on foreign supply if we run short. That just raises the question of why we should not save money and stockpile the lot.

The prospects for local production aren't even as good as that. Guided weapons are complicated things, so there's no chance that Australia will make complete missiles of any type.

The really tricky component is the sensor in the nose, the device that sees the target and directs the weapon to home in. Making that in small numbers here is hardly conceivable, and if it is part of an advanced US weapon we just won't be allowed to see the technology needed to do it.

So, even for a limited range of products, missiles made here would not in fact be entirely made here. The most costly parts would have to be imported. To assure wartime supply, we'd have to stockpile those parts. And that just raises the question "Why not stockpile complete missiles?"

US missile factories are busy just now; securing supply from them is not easy. But setting up factories here would still cost more than placing orders that US companies could use to fund expansion.

This brings us back to that interesting word "boondoggle". In the very first sentence of Morrison's March press release, we hear about how the project will create jobs - which we might, with shocking cynicism, read as "attract votes".

Further down, we read that this project will be "providing thousands of local jobs in businesses right across the defence supply chain".

And "this could create well over 2000 jobs in different locations across the nation".

Yes: different locations, different electorates. We get the picture.