Last week there was a meeting in the US where our top intelligence official testified to lawmakers
Senators Warned of Terror Attack on U.S. by July
It contains this interesting bit.
At Tuesday’s hearing, Senator Dianne Feinstein, Democrat of California and chairwoman of the Senate Intelligence Committee, asked Mr. Blair to assess the possibility of an attempted attack in the United States in the next three to six months.
He replied, “The priority is certain, I would say” — a response that was reaffirmed by the top officials of the C.I.A. and the F.B.I.
I'm not entirely sure what that means, I doubt anyone really knows, the comment was probably meant to be ambiguous. Such a question is probably nonsense, but anyone looking to keep their job is going to tell you it's almost a certainty. If someone says anything else, then there is a terrorist attack, they're going to be blamed for whatever breakdown in intelligence happened and have to find a new job.
One of the unfortunate parts of being accountable for security is having to answer questions. It's easier to say an attack is imminent, then get praised for "preventing" it, than to say probably not and having to answer for the failure. All aspects of security work like this unfortunately. As long as everything is going great, nobody cares, then when something bad happens, it's all your fault. Intelligence people keep themselves known by constantly stating that something bad is about to happen any day now.
The right question to ask any security person isn't to predict the future, rather "What are you doing to minimize our risk?"
There is a saying about the old Berlin Wall, "Nobody ever escaped the same way twice." Security is no different. Rather than try to guess what the next attack will be, you should have all around good practices that not only help prevent attackers from targeting you, but then minimize damage when they do attack. We can easily guard against the past, but predicting the future is impossible.