While we grieve over the atrocities of the terror attack last Saturday, many may wonder why it occurred in Kunming. Why, if the attackers' minds were truly on Beijing, where China's top legislature would convene several days later, did it occur where it did?

Terror theory is simple: Seeking notice and to influence public opinion, terrorists often identify targets with high public visibility, global media exposure or symbolic meaning. And Beijing fits the bill better than any other city.

So why Kunming?

One answer might be that the Chinese capital has a formidable metropolitan police force, employing tens of thousands of officers and boasting the best SWAT teams in the nation.

But the Beijing police may beg to differ: In a city of more than 20 million and with many high-value terror targets, its force of 60,000 or so is already stretched thin and overworked.

That calculation changes drastically, however, when the city's huge army of public security volunteers - hundreds of thousands of them - is added. While a definite number is not available for the current legislative and political advisory meetings, it has been estimated that more than 700,000 such volunteers are mobilized each year to ensure the security of the annual two sessions in the capital.

One important mission of the volunteers is to provide safety and security for the representatives. Around the hotels where representatives stayed in 2010, volunteers wearing red armbands were posted at 30-meter intervals from 7 am to 10 pm every day, according to Chinese media reports.

If these volunteers, mostly retirees and temporary workers, are not a strong enough deterrent to terrorists by themselves, think about the elaborate intelligence network they have built to detect crimes and enable swift police action.

Informants with government allowances are appointed in each neighborhood, while 15,000 inspectors make the rounds of communities of migrants every day to detect the earliest signs of security problems. One in every 25 security volunteers has the responsibility of intelligence gathering.

The plan, called Mass Prevention and Mass Management, has taken off since the Beijing Olympics in 2008, when it proved a powerful tool for crime prevention and control. During the Games, police and volunteers kept a close watch on tens of thousands of people classified as high risk, which significantly reduced crimes compared with the same period in previous years.

The system is also cost-effective, as the city taps into a renewed spirit of volunteerism among its citizens. Ordinary volunteers are usually paid only with uniforms, armbands and meals, although the city provides rewards at the end of each important security job. Cash prizes of up to 500,000 yuan ($81,720) are given to those who provide valuable tips to prevent or solve crimes.

But as a means of interdicting terrorism, the much-touted security model faces obstacles that impede its replication in other provinces and cities. Issues such as the legality of volunteers performing law-enforcement tasks, the welfare of volunteers in the line of duty and inadequate funding for security operations, need to be sorted out.

Modern city residents may also feel uncomfortable with intrusive and omnipresent security measures. Granny patrols in Beijing were once stigmatized as busybodies who liked to put their noses into other people's business.

But public monitoring has gained traction, in light of limited police manpower and technology, as the best available way to stay on top of terrorism.

Even with Mass Prevention and Mass Management in place, the capital's security is not airtight. In October, three members of the Uygur ethnic group drove a jeep into a crowd of people at Tian'anmen Square, in the heart of the city, killing two and injuring another 40, before killing themselves by igniting gasoline in the vehicle.

But the continuous presence of volunteers has proved its value.

The Kunming stabbings might have happened in Beijing but for the heightened vigilance provided by a small army of citizens who take seriously the job of watching out for our safety.

Let's show more respect for these volunteers next time we see them on the streets, in shopping malls or at our doors.

The writer is editor-at-large of China Daily. E-mail: [email protected]