Showing posts with label security. Show all posts
Showing posts with label security. Show all posts

Friday, June 09, 2006

A reasonable percentage (3)

One piece of intelligence was accurate.
A man described as Abu Musab al-Zarqawi's "spiritual adviser" inadvertently led US forces to the spot where the militant leader was finally located and killed, the US military says.

Major General William Caldwell said the operation to track down the most wanted man in Iraq was carried out over many weeks, before he was killed after two US air force F-16s bombed a house in a village north of Baghdad.

"The strike last night did not occur in a 24-hour period. It truly was a very long, painstaking deliberate exploitation of intelligence, information gathering, human sources, electronic, signal intelligence that was done over a period of time - many, many weeks," Gen Caldwell said on Thursday.


One piece of intelligence was flawed.
Anti-terror police raided a house at Forest Gate last week after saying they received "specific intelligence" that a chemical device might be found there.

Scotland Yard later said they had "no choice" but to act while the prime minister said it was essential officers took action if they received "reasonable" intelligence suggesting a terror attack.

Tony Blair said he backed the police and security services 101% and he refused to be drawn on suggestions that the armed operation had been a failure.


It's a reasonable percentage. (Previous posts: April 9th, April 18th.)

But that's part of the problem with intelligence - it delivers probability rather than certainty. Perhaps the outcomes are the right way around this time - the presumed-guilty man was killed, and the presumed-innocent man merely injured. (So we shouldn't complain, should we? Imagine the complaints if it had been the other way around!)

But over the long run, are there too many errors? (Difficult to tell, as we only know of some of the better publicized successes and failures.) Should we be uneasy about the errors of intelligence, and the consequences of acting upon erroneous intelligence? There are fundamental questions here about the relationship between knowledge (or ignorance) and action (or inaction).

Tuesday, April 18, 2006

A reasonable percentage (2)

"It seems like every time someone tests airport security, airport security fails. In tests between November 2001 and February 2002, screeners missed 70 percent of knives, 30 percent of guns, and 60 percent of (fake) bombs. And recently, testers were able to smuggle bomb-making parts through airport security in 21 of 21 attempts."
[Bruce Schneier]

If security finds nearly half the bombs, does that count as success or failure? (Glass half-full or half-empty?) Schneier reckons it's probably good enough, and points out: "Against the professionals, we're just trying to add enough uncertainty into the system that they'll choose other targets instead."


"Do not despair; one of the thieves was saved. Do not presume; one of the thieves was damned."
[Saint Augustine]

"One of the thieves was saved. (Pause.) It's a reasonable percentage."