Wanting one thing and wanting, or not wanting, another can stand in various kinds of relation, some of them straightforwardly visible, others a bit more obscure. Here are some simple examples.
(1) You want A and you want B, but circumstances make it impossible for you to fulfil both wants. You'd like to be at the bookshop where one of your favourite writers is speaking and you want to be at the game, but the two events are taking place at the same time. So you go to one and you miss the other. Note that your choice of what to see and what to miss doesn't necessarily mean that you give up wanting to be at the event you miss. A person can have inconsistent wants.
(2) You want C and you don't want D, but you're unaware that if you get C you'll also get D, because D is a consequence of C that you don't know about. Thus, you want another slice of that delicious cake, though it's going (for some reason I leave to one side) to make you ill. In saying that you want another slice of cake, you're not committed to the proposition that you'd like to start feeling ill, even though feeling ill will be the consequence of having the second piece of cake; it is opaque to you that this is the consequence, so your statement that you want cake doesn't entail that you also want an almighty stomach ache.
(3) You want E and you don't want F, F is a possible but not inevitable consequence of trying to get E, and there are also some consequences of not trying to get E that might be as bad as F or worse. You then have a problem which you have to think about. Wanting E, let's say, is trying to maintain your health in a reasonable state over the next few years, and you've been advised that to do this you need to undergo some medical procedure to which a risk is attached. There is a bad possible consequence - F - of the medical procedure, but it may not happen. And choosing not to have the medical procedure, you are told, may also have bad consequences of F-type proportions. You deliberate.
(4) You want G. And one way of getting G is H, something which you really shouldn't want. Let's say, you want to be right against people who have disagreed with you, and one way of your being right and their being wrong is for things to go very badly for a lot of other people. I mean, very very badly. The relationship between wanting G and wanting or not wanting H is, then, quite transparent - as clear as in (1) and with none of the opacity of (2) or the complication of (3).
This last example fits the passage from Matthew Parris here, where he is detecting an appetite for apocalypse at the turn of the year:
Take Iraq, Afghanistan and the War on Terror. It is not the hawks, neocons and hardliners alone who half-will a strike by the forces of evil so horrific in scale as to be a knockdown vindication of what they said all along. Many of the antiwar brigade, too - we who from the start have railed against the occupation of Iraq - have in our secret hearts suppressed a twinge of disappointment that the surge of US troop reinforcements in Baghdad has been accompanied by a reduction in civil atrocities. We kind of thought - did we? - that the whole place was going to go up in one enormous explosion, leaving almost everybody dead, and settling the argument finally in our favour?Perhaps Parris isn't being serious. Whether he is or not, I'd be interested to know how he thinks he can know that there is, among 'hawks', a desire for vindication even at the cost of a strike that is 'horrific in scale'. He's well placed, naturally, to speak for himself - if not necessarily for others on his side of the relevant division of opinion - in confessing a disappoinment that things in Iraq, bad as they now are, aren't quite as bad as they might have been. But it's better for him if he's being facetious. For, though most of us are subject to the temptation of wanting to be right, there are fewer who want this want to be satisfied where the cost of its being satisfied is death and destruction to others.