Vigilance against potential terrorist attacks and measures to handle their destructive aftermath are not mutually exclusive, but necessarily complementary (Replace defeatist anti-terror campaign with push for vigilance by Mr Chia Boon Teck; March 10).

Well-patrolled and guarded as Singapore's coastline and checkpoints are, the borders are still porous.

Terrorists may not even need to be physically in our country to wreak heinous havoc, as seen when some suspects arrested in Indonesia last year were accused of a plot to launch a rocket at Marina Bay from Batam.

With the ubiquity of drones - the purchase and ownership of which are uncontrolled - an attack from the air or from high-rise buildings is easy to engineer and almost unpreventable.

When I was with the Singapore Civil Defence Force, every in-camp training session was dedicated to the repeated drilling and practice of handling civil disasters.

Yes, prevention is always better than cure.

It is a given that it is every citizen's responsibility to remain vigilant against terrorism.

The Government's role is to coordinate the massive efforts needed to prevent disaster, and to contain its aftermath.

That, after all, is the entire essence of civil defence.

Yik Keng Yeong (Dr)