In the following interview excerpt (source) from a few months ago, then-President George W. Bush misunderstood Charles Gibson in a way that I've just realized has implications for a hotly-debated but obscure-for-the-ordinary-person philosophical debate:
GIBSON: You've always said there's no do-overs as President. If you had one?
BUSH: I don't know -- the biggest regret of all the presidency has to have been the intelligence failure in Iraq. A lot of people put their reputations on the line and said the weapons of mass destruction is a reason to remove Saddam Hussein. It wasn't just people in my administration; a lot of members in Congress, prior to my arrival in Washington D.C., during the debate on Iraq, a lot of leaders of nations around the world were all looking at the same intelligence. And, you know, that's not a do-over, but I wish the intelligence had been different, I guess.
GIBSON: If the intelligence had been right, would there have been an Iraq war?
BUSH: Yes, because Saddam Hussein was unwilling to let the inspectors go in to determine whether or not the U.N. resolutions were being upheld. In other words, if he had had weapons of mass destruction, would there have been a war? Absolutely.
GIBSON: No, if you had known he didn't.
BUSH: Oh, I see what you're saying. You know, that's an interesting question. That is a do-over that I can't do. It's hard for me to speculate.
Here are the two ways to read Gibson's question "If the intelligence had been right, would there have been an Iraq war?":
1. Holding the content of the intelligence the same as it is in the actual world, the rest of the world would have to have been different for the intelligence to have been right. If that situation were true, would the war have occurred? In other words, if what the intelligence reports actually said had turned out to be true, and Iraq's WMD programs were not just on hold because of sanctions, if there had been stockpiles of WMD in fact, would we have invaded Iraq?
2. Holding the rest of the world constant, for the intelligence reports to have been true, they would have had to say something different from what they actually said. If that situation were true, would the war have occurred? In other words, if the intelligence reports had said only that Saddam Hussein's WMD programs were not actively producing weapons but were merely on hold so that he could have such weapons within a year if the sanctions ended, would there have been a war?
It's hard to say which interpretation is more natural. I can see how Gibson's might be thought to be more natural, because there doesn't seem to be any reason to ask the question if he'd meant what Bush took it to mean. But for the hearer to come to that conclusion, it requires being aware of both interpretations and considering that the first wouldn't be worth asking in comparison with the second. Most hearers interpreting it in a way that seems most natural to them will probably hear it one way or the other, and thus (like President Bush) won't be going through that reasoning process to conclude that the second is the more likely intent.
On the other hand, I can see how someone might more naturally take it the way Bush did. I can think of a much clearer way to ask what Gibson wanted to know. He could have asked what would have happened if we'd had better intelligence or more accurate intelligence. By referring to it as "the intelligence", Bush took it to be referring to the actual intelligence. It's a lot harder to find an alternative way to say what Bush took it to mean. You'd need a much more roundabout expression like "if the information we based the war on from intelligence reports had turned out to be the accurate description of Saddam Hussein's WMD status".
I thought that was an interesting ambiguity, anyway.
[Sidebar to philosophers: At first I thought it had larger implications, because it seems very close to a debate in the semantics of counterfactual expressions. David Lewis takes counterfactual claims of the form "If A were true, then B" to mean that in the closest possible world (by which he means the possible world as much like ours in material composition) where A is true, B is also true. I've always found that view implausible, and I had at first thought this would be a good test case for people's intuitions on that matter. But then I realized that Lewis' theory is a theory for the truth conditions of counterfactual propositions. This is a case where it's ambiguous which proposition is even meant, not a case of how to evaluate whether a clear counterfactual proposition is true.]