Caught

Here's an awful sentence from a Salon.com article about how China is manifestly unready to host the Olympics coming up in less than six months:

When a world champion long-distance runner like Ethiopia's Haile Gebrselassie bows out of the Olympic marathon -- citing fears that Beijing's polluted air will aggravate his asthma, the message sent to the rest of the world isn't one of Chinese success, but failure -- a failure to balance economic growth with the maintenance of a basic quality of life.

Dashes (represented here by doubled hyphens) act more or less like parentheses or commas; they trap something inside, something which is meant as a commentary or modifier to the main flow of the sentence. But to perform this function, they have to come in pairs: a bear-trap with only one jaw isn't going to do a thing. (Sometimes, the second dash can be replaced, but only at the end of a sentence, and only by a period, a question mark, or an exclamation mark.)

The sentence in question has two parenthetical clauses, but only two dashes (and one period). This makes for an extremely confusing sentence, to say the least, because it looks as if everything inside the existing dashes is a single clause. Put the missing dash after the word "asthma" and the whole thing suddenly makes perfect sense.

Some people think you shouldn't use dashes at all, that they're a clumsy replacement for more established punctuation such as the colon and the semicolon, that they encourage sloppy sentence construction. I kind of like them--I think they're a little breezier and less formal--but in a case like this, I can see the point. I'd never write a sentence with two pairs of dashes, anyway: the second pair in the quoted sentence (well, dash-plus-period, which amounts to the same thing) ought to have been replaced by a colon and a period.

Where are the copy editors when you need them? Not at Salon, that's for sure.