This has been done many times in the past, e.g 27 Dec 1985 Rome and Vienna airports. Unfortunately airport security must start from before entrance into the Terminals, if the terrorists today decided to attack simultaneously LHR, CDG, BRU, AMS, LIN/MXP and so on as an example, the entire economy of Europe will be in serious trouble together with the lives of millions of people in addition to the casualties on the ground. It is too easy to do and airports are excellent targets in the eyes of terrorists. I know we cannot cover and screen the entire transportation hubs in each country but airports are too important and if we do not act now there will be more attacks like this one. It has been another very successful attack in the eyes of the terrorists, and we cannot disagree, this is a war, they have done it before and they will try to attack our airports again, unless we stop the attackers before those suitcases full of explosive together with their AK47 rifle reach the check in area and Terminals. There is nothing more clever we could do now..
If we do not act now more airports will very likely be attacked in the same way. I am sure, would be terrorists keep emulating their colleagues and this attack is huge publicity for them and their tactics. Review of airport security to include landside will be painful and very frustrating but we have no choice I am afraid.