If that weren't the case, the TSA would have simply banned all liquids.
By all indications, the 9/11 bombers were very high on the AQ food chain. The underpants bomber didn't get tens or hundreds of thousands of dollars wired to him before the op; he was a shmuck, in a strategy designed to weaponize schmucks.
If a TSA measure doubles the manpower required to carry off an AQ op, it is almost prima facie "effective". Is, I think, the logic you'd deploy against the "combine the 3oz bottles" argument.
Of course, we're now talking about a _conspiracy_ - and a conspiracy of four average people is 100x more likely to be discovered by a intelligence team than a single attacker.
So perhaps it's the forcing of attacks to be _conspiracies_ is the goal of allowing only small amounts of liquids.
Regardless - I think we can all agree that it makes liquid bomb attacks substantially more difficult than simply allowing people to carry on as much liquid as they chose, and therefore opening the door wide open to a lone attacker just blowing up airplanes at will without possibility of detection.
Paradoxically, the best terrorist strategy (as long as they have enough volunteers) under unpredictable screening may be to prepare a cadre of suicide bombers for the least rigorous screening to which they might be subjected, and not, as the strategy assumes, for the most rigorous. Sent on their way, each will either succeed at destroying a plane or be caught, but either outcome serves the terrorists' objective. ...
We might reflexively assume that any passenger screening system needs to be 100% effective at detecting all possible weapons and dangerous objects, an obviously difficult task. But, fortunately, that's not the requirement. Instead, the mechanisms need only be highly effective at detecting objects that can create actual terror under the conditions they will be subjected to in an actual flight. That is, in order to have meaningful security screening, we first must understand what it realistically takes to bring down an airplane. The security system can then be designed specifically to eliminate the preconditions for successful terrorism.
The TSA's much maligned "three ounce" liquid rule is, in fact, a nice example of good security engineering of this kind. ...