Is " .. the war on drugs has not, and cannot, be won." correctly punctuated?
The quote in the title of this post is an extract from the official report by the Global Commission on Drug Policy, authored among others by Kofi Annan. To me the comma is clearly misplaced. But is the following any better?
The war on drugs has not, and cannot be, won.
Or, to avoid incorrect ellipsis, must it be:
The war on drugs has not been, and cannot be, won.
I don't think it's wrong. Searching Google books finds 383 results for "has not and cannot be", and 346 for "has not been and cannot be". Searching Google finds 402 and 366 results for these phrases. All the ones I checked mean "has not been and cannot be". Most of these have no commas, but when the commas are put in, they are placed as "has not, and cannot, be" and "has not been, and cannot be,".
The idea is that when you fill in the ellipsis in
has not and cannot be
you change the tense of the verb "be" to match "has not". This kind of change in verb tense is done routinely, and has been called non-parallel ellipsis.
For example, if you say
The twins run quickly, and Mary, slowly,
the full sentence is "Mary runs slowly", not "Mary run slowly". Similarly, to use an example I found on the web,
This information could have been released by Gorbachev, but he chose not to.
Here, the full phrase isn't "he chose not to released it", but "to release it".
The rules of English grammar undoubtedly allow you to change the tense of verbs for ellipses in some situations and not in others. Given the usage statistics, I would claim that this is one of the situations where it is allowed.
On the other hand, adding been here only adds a short word to your text, and makes is somewhat less confusing. In writing, you might as well put it in.
To give an example that shows that non-parallel ellipsis is sometimes the preferred interpretation in English in a seemingly ambiguous case, as it is in the OPs example, consider:
John would have left, but Mary won't.
I don't think anybody would complete this to "but Mary won't have left"; the natural interpretation is "but Mary won't leave", even though the first is strictly parallel and the second is not.
The kind of ellipsis in the example is fairly common, but it doesn't make for easy reading. On analysis, it seems to mean The war on drugs has not won and cannot be won, a kind of stalemate, assuming a war can actually do such a thing as win. That is a possible interpretation, but I imagine what is meant is The war on drugs has not been won, and it cannot be won, an admission of defeat. In that case, The war on drugs has not been, and cannot be, won shortens the sentence in a way that retains the intended meaning, but I'd find it just as easy to read without the commas.