U.S. Increased Security on Flights to Scotland 2 Weeks Ago

It is clear that the U.S. authorities, despite denials, knew that an attack was imminent in Britain. The questions is what did they know and what was done to prevent the terror attacks, which obviously failed. And how reliable is our intelligence capability in preventing terrorism:

Security aboard flights into Glasgow Airport was beefed up two weeks ago with protection by U.S. air marshals who are now on board every inbound and outgoing European flight, according to a Homeland Security official.

Air marshals also began guarding flights into Prague at the same time, and in May stepped up coverage to guard all flights into and out of Germany, where terrorists are reportedly in the advanced planning stages of an attack. Air marshals are also guarding some flights into South Asia airports.