Build city walls to contain southern extremism

I live in Chiang Mai and travel this region often, the city walls always striking. City walls to keep out barbarian raiders and enemy attacks. 
Could modern city walls help security in the south? Help to establish “safe zones”? 
In the world today and throughout history there are examples of such tactics working effectively. Israel today, or security cordons around major international events, for example.
In Malaya the British used this tactic to counter the Chinese insurgents. 
They gathered the population in to the towns and camps and walled them. Checks were carried out on everyone coming and going. It ended attacks on urban areas. Once this was done, patrols and searches of the suburbs kept pressure on the insurgents. The insurgents retreated to the forests and Special Forces hunted them down. The British were victorious. Today’s age of digitised data would make keeping track of the citizenry much more easily. Checks on movements in and out of the towns correlated to attacks could identify more suspects. 
The Thai army has drones on order already. These could be used to follow such suspects clandestinely from high altitude and so gather intelligence. 
Once safe zones are really safe the peace loving people would choose to move in to those areas as peace and prosperity, trading and tourism pick up – thus making the insurgency increasingly impotent and unpopular.
Marcus Cesare 
(From Facebook)