Two recent examples are the November 2015 Paris attacks, where the killers slipped into Paris from Belgium, and last December's attack in Berlin, where the suspect managed to flee Germany and reach Italy via France.
We live in difficult times.
It is manifestly hard to balance basic freedoms with the potential security threats those freedoms pose to innocent people.
I hope Asean will ensure that the most comprehensive security measures are in place as member states forge a single shipping and aviation market and make border crossings easier for buses.
Europe's Schengen Agreement allows the free movement of people across the borders of 26 countries. While it facilitates trade and tourism, it also allows criminals to go into a country, commit crimes and flee to other countries easily.
ทีี่มา : http://www.straitstimes.com/forum/letters-in-print/europes-open-borders-hold-lessons-for-asean