A man comforts a woman outside Brussels Airport after explosions rocked the departure lounge, killing at least 14 people on Tuesday. [Photo/Agencies]

The death toll may not be the heaviest, yet the multiple blasts at the Brussels airport and a metro station were cause for serious concern.

Because they occurred in the heart of Europe, at a time when the European Union remains on high alert after the attacks in Paris on Nov 13 and when countries were preparing and prepared for further attacks.

Particularly so in Brussels where the police were being ultra-vigilant in anticipation of reprisals after a suspected participant in the Paris attacks was arrested in the city four days ago.

As Belgian Interior Minister Jan Jambon said on Monday, his country was on high alert for a revenge attack.

And because of this, the fear and panic the blasts caused, as intended, which led to the airport being evacuated and the closure of the subway system, spread far beyond the bloodshed.

For while the Brussels attacks may be acts of despair by cornered terrorists as a result of the tireless manhunt closing in, there is the suspicion they may be evidence that terrorist cells remain both active and capable despite the efforts being made to track them down.

If that is the case, the fact that they can attack amid such vigilance means they can probably do so at any other time. Especially since no country can afford to remain on high alert indefinitely.

And if they can strike in Brussels, they can do so in other places, because not everywhere can afford the degree of preparedness the city had demonstrated.

The situation is even more worrisome considering the chaos recent refugee inflows have brought about. Not to mention the rumors that terrorist organizations are taking advantage of the crisis to infiltrate Europe.

The attacks in Paris, along with the sexual assaults in Germany, had already prompted calls for reevaluating the approach to refugees. What happened in Brussels will only amplify those calls.

While the attacks have again revealed Europe's vulnerability to terrorism, that is no excuse for complacency by other countries. We cannot afford to ignore the essential underlying message that no country is safe nowadays, as globalization makes it easier for terrorist groups to operate across borders.

The current anti-terror campaign has been less than effective, in part, because the international community has yet to come up with a meaningful alliance that is truly united in its efforts to combat terrorism. And a united front is out of the question if countries cannot even agree on what constitutes terrorism.