The attacks in Brussels which left at least 31 dead and nearly 300 injured has raised the issue once again as to how such attacks might be prevented in the future.
Terrorists affiliated to ISIL set of explosives in an airport check-in area and at a Metro station, both soft targets and areas which until now have been left relatively unguarded.
Growing security
Following aircraft hijackings and the threat of bombs being placed on board planes airline security has been significantly tightened.
After 9/11 knives and sharp objects were banned. Soon after restrictions increased further with passengers being forced to remove their shoes for inspection after the so-called Shoe Bomber Richard Reid attempted to detonate explosives in his footwear. That incident also precipitated the ban on matches and lighters.
A plot uncovered by British and American investigators suggesting terrorists might be planning to use liquid explosives smuggled on board aircraft disguised as soft drinks resulted in a ban on all liquids being carried.
Some restrictions have been relaxed slightly. Some airlines, though not all, allow a single lighter to be carried on one's person. And liquids in small quantities such as a 100ml tube of toothpaste, may now be carried in carry-on baggage. Knives and other sharp objects remain on the banned list, however.
Such restrictions have undoubtedly prevented attacks. But they have had had other effects. The increased security has made travelling more difficult and often confused. The tight controls have merely forced terrorists to look for easier targets.
Terrorists affiliated to ISIL set of explosives in an airport check-in area and at a Metro station, both soft targets and areas which until now have been left relatively unguarded.
Growing security
Following aircraft hijackings and the threat of bombs being placed on board planes airline security has been significantly tightened.
After 9/11 knives and sharp objects were banned. Soon after restrictions increased further with passengers being forced to remove their shoes for inspection after the so-called Shoe Bomber Richard Reid attempted to detonate explosives in his footwear. That incident also precipitated the ban on matches and lighters.
A plot uncovered by British and American investigators suggesting terrorists might be planning to use liquid explosives smuggled on board aircraft disguised as soft drinks resulted in a ban on all liquids being carried.
Some restrictions have been relaxed slightly. Some airlines, though not all, allow a single lighter to be carried on one's person. And liquids in small quantities such as a 100ml tube of toothpaste, may now be carried in carry-on baggage. Knives and other sharp objects remain on the banned list, however.
Such restrictions have undoubtedly prevented attacks. But they have had had other effects. The increased security has made travelling more difficult and often confused. The tight controls have merely forced terrorists to look for easier targets.
Moving goalposts
Tuesday's attack at Zaventem Airport was a clear indication of such a shift in methods. Unable to breach airport security and target an aircraft, terrorists simply switched to the check-in area.
In some respects the attack was more devastating than if they had managed to bring down or destroy a plane. While more lives would certainly have been lost should a plane have been destroyed, as was seen following the downing of a Russian aircraft last year, the disruption caused by this week's Airport terminal bombing could have far reaching implications.
One of Belgium's main airports has essentially been shut for weeks, if not longer. And now security officials around the world may have to find ways to prevent similar attacks from happening again.
Tuesday's attack at Zaventem Airport was a clear indication of such a shift in methods. Unable to breach airport security and target an aircraft, terrorists simply switched to the check-in area.
In some respects the attack was more devastating than if they had managed to bring down or destroy a plane. While more lives would certainly have been lost should a plane have been destroyed, as was seen following the downing of a Russian aircraft last year, the disruption caused by this week's Airport terminal bombing could have far reaching implications.
One of Belgium's main airports has essentially been shut for weeks, if not longer. And now security officials around the world may have to find ways to prevent similar attacks from happening again.
Security rethink
This is easier said than done. Though it is not impossible. The simplest method might be to implement screenings at the entrance to the main terminal itself.
Such screenings can already be seen in China. At Chengdu's international airport armed security personnel check people's luggage as they enter the building, wiping bags with swabs.
How practical this might be in Western airports is unclear. Indeed such security measures may only shift the terrorists' focus, perhaps to the drop-off area, parking lots or even the main roads into the airport.
Do we then employ road blocks and check points? How long before a whole country becomes a fortress? Or do we change our focus and instead target Islamic terrorism more seriously and strike them before they strike us? Even this might be easier said than done.
Blinkered governments
As Andrew Neil from the BBC politics program This Week pointed out there may be between 400 and 600 ISIL trained terrorists deployed across Europe, ready to strike and bring more death and terror to the streets of capital cities.
"When the same Islamist scumbags who'd brought carnage to Paris in November visited their barbarous death cult on the people of Brussels," they left "our politics parochial, even pathetic in its wake," Neil said.
"It's far from clear even after Paris and Brussels, that Europe's powers that be have any real idea of the scale of the threat and the daunting counter insurgency task before us; and it's something that we shall have to pay our part in addressing."
Fears and reactions
The attacks in Paris and Brussels and the threat of another attack in another European city has certainly raised fears amongst regular travellers. However most people say they refuse to let the fear of attacks cower them since this only hands a victory to the terrorists.
Nonetheless, the terrorists have already won tacit victories in that our lives have changed significantly with increased security checks and armed forces deployed upon our streets. And while Belgians have been resolute in their opinion not to let the terrorists win, organisers of a "March against fear" have were forced to call off a planned rally in Brussels this weekend for security reasons, at the request of authorities [BBC].
It is easy to recoil against the kneejerk reaction of increased security, more bombing raids in Syria and Northern Iraq and more surveillance. But we have to acknowledge there is a war being waged against the West and its interests by extreme Islamic groups. These groups must be identified, sought out and destroyed. And uncomfortable as it may be Europe's security and intelligence services must ignore any politically correct sensibilities and seek out the insurgents who are hiding in plain sight within Muslim communities across Europe. Peaceful Muslims too must be more proactive too and help identify any amongst their community who have strayed towards violent Jihad and pass along the information to authorities.
No-one can ignore the threat, be it governments, security services, ordinary citizens and indeed Muslim communities amongst which these terrorists attempt to hide. And all must play a part in rooting them out.
tvnewswatch, Yunnan, China
This is easier said than done. Though it is not impossible. The simplest method might be to implement screenings at the entrance to the main terminal itself.
Such screenings can already be seen in China. At Chengdu's international airport armed security personnel check people's luggage as they enter the building, wiping bags with swabs.
How practical this might be in Western airports is unclear. Indeed such security measures may only shift the terrorists' focus, perhaps to the drop-off area, parking lots or even the main roads into the airport.
Do we then employ road blocks and check points? How long before a whole country becomes a fortress? Or do we change our focus and instead target Islamic terrorism more seriously and strike them before they strike us? Even this might be easier said than done.
Blinkered governments
As Andrew Neil from the BBC politics program This Week pointed out there may be between 400 and 600 ISIL trained terrorists deployed across Europe, ready to strike and bring more death and terror to the streets of capital cities.
"When the same Islamist scumbags who'd brought carnage to Paris in November visited their barbarous death cult on the people of Brussels," they left "our politics parochial, even pathetic in its wake," Neil said.
"It's far from clear even after Paris and Brussels, that Europe's powers that be have any real idea of the scale of the threat and the daunting counter insurgency task before us; and it's something that we shall have to pay our part in addressing."
Fears and reactions
The attacks in Paris and Brussels and the threat of another attack in another European city has certainly raised fears amongst regular travellers. However most people say they refuse to let the fear of attacks cower them since this only hands a victory to the terrorists.
Nonetheless, the terrorists have already won tacit victories in that our lives have changed significantly with increased security checks and armed forces deployed upon our streets. And while Belgians have been resolute in their opinion not to let the terrorists win, organisers of a "March against fear" have were forced to call off a planned rally in Brussels this weekend for security reasons, at the request of authorities [BBC].
It is easy to recoil against the kneejerk reaction of increased security, more bombing raids in Syria and Northern Iraq and more surveillance. But we have to acknowledge there is a war being waged against the West and its interests by extreme Islamic groups. These groups must be identified, sought out and destroyed. And uncomfortable as it may be Europe's security and intelligence services must ignore any politically correct sensibilities and seek out the insurgents who are hiding in plain sight within Muslim communities across Europe. Peaceful Muslims too must be more proactive too and help identify any amongst their community who have strayed towards violent Jihad and pass along the information to authorities.
No-one can ignore the threat, be it governments, security services, ordinary citizens and indeed Muslim communities amongst which these terrorists attempt to hide. And all must play a part in rooting them out.
tvnewswatch, Yunnan, China