Slate has an excellent article about the attempted car bombings in UK.

Important quote:

The London bombs failed because open, Western societies are more resilient than we sometimes think they are. The police found one of the Piccadilly car bombs because an ambulance crew, responding to an unrelated call, saw smoke seeping from its trunk and alerted the police. The other car was illegally parked, and London’s supervigilant, much-hated traffic wardens towed it to a parking lot, where someone noticed that it smelled of gasoline and alerted the police. That Britain has functional ambulance services and working traffic wardens, all of whom are civic-minded enough to call the police when they suspect something is amiss, may not sound extraordinary. But these are precisely the kinds of institutions that are missing in many places, among them Baghdad, a city where parking isn’t exactly a public preoccupation, and where the civic-minded avoid police who are, fairly or unfairly, suspected of everything from ethnic cleansing to taking bribes.

The article isn’t too long, and is worth a read.