It's a scorching day and the breezy beaches and air-conditioned shopping malls beckon Singapore's youth, but for hundreds of teenage boys, hanging out is totally out of the question. The latest recruits for the city-state's mandatory National Service (NS) program are sweating their way through basic military training at Pulau Tekong, a fortified Singaporean island bristling with rifles and testosterone.
"Where's your aggression?" an officer growls at trainees, their pimply faces grimacing under camouflage paint as they kick at imaginary enemy troops or squirm on their backs to make it past a prickly canopy of barbed wire.
Elsewhere on the island, trainees march in tight columns, undergo marksmanship training and learn parade precision in the shadow of jetliners taking off and landing at Changi international airport.
All able-bodied boys in Singapore, including both citizens and permanent residents, are eligible to be conscripted for two years of full-time military service once they turn 18.
"Whether you are Malay, Chinese or Indian, or any other race, whether your father is rich, your father is a hawker, or your father is a banker, we put them in together to train together," says Colonel Winston Toh, the military's director of national service affairs.
Not that the kids have much choice. Any eligible Singaporean boy who fails to turn up for National Service can be prosecuted. If he is convicted, the penalty is imprisonment for up to three years or a fine of up to 5,000 Singapore dollars (3,000 US), or both.
While some parents and youngsters see it as an interruption in studies and careers, others accept it as an inevitable, and beneficial, rite of passage for Singaporean boys.
Bespectacled recruit Andy Lee, who had just completed junior college, looks sullen and a little dazed when he arrives with a fresh batch in Pulau Tekong.
He hugs his parents tightly when it is time for them to leave him on the island for two weeks of orientation, after which he will enjoy weekends off.
"I'm definitely ready for NS. It's time, it's now my turn," he says.
Pulau Tekong is where it all begins for fresh recruits, with nine gruelling weeks of basic training before they are farmed out to officer school or duties in the various armed services.
After their National Service stint, they join the reserves and resume their education or enter the workforce. Reservists are called up annually until their mid-thirties to refresh their skills and make sure they remain physically fit.
The NS program was launched two years after Singapore's bitter separation from Malaysia in 1965. Singapore's long-term prospects at the time were uncertain, its phenomenal rate of industrialisation just a dream.
"We thought it important that people in and outside Singapore know that despite our small population, we could mobilise a large fighting force at short notice," founding prime minister Lee Kuan Yew wrote in his memoirs.
Singapore got crucial help from Israel, which sent advisers to help set up its armed forces in 1965 after other countries refused. But there was the risk of a backlash from Muslims in the region against the presence of Israelis.
"To disguise their presence, we called them 'Mexicans'. They looked swarthy enough," Lee wrote, adding that a large standing army would have been costly and conscription "would bring political and social benefits".
Four decades later, Singapore can call up some 350,000 fighters within hours for combat, mostly reservists trained under the National Service program, a staggering number for a country with just 3.4 million citizens and permanent residents.
Backed by Southeast Asia's most lethal military arsenal - thanks to heavy defence spending and explosive economic growth - this "people's army" serves as a powerful disincentive for any country to mess around with Singapore.
"The whole defence concept is anchored on two very fundamental principles. One is diplomacy, the second one is deterrence," Colonel Toh tells AFP in an interview in a suburban camp.
"If all else fails and really there's no choice, we must have the capability to deter people from even thinking about any ill intent at all."
Colonel Toh says Singapore's defence policies underpin the stability that has brought in massive foreign investment through the years, and National Service promotes social cohesion in the multi-racial, predominantly ethnic Chinese immigrant society.
To test the readiness of reservists, coded messages periodically appear on cinema and television screens alerting members of specific units to turn up at rendezvous points in full military uniform, under pain of a fine.
In the event of a real war, they would be handed rifles and ammunition.
Because of its small land area and high population density, Singapore also sends trainees to friendly countries like Thailand, Taiwan, Brunei and Australia for exercises.
Permanent residents who reach the cut-off age must undergo the same military training if they want to continue living in Singapore. As a result, children of westerners or mixed-raced couples train alongside "native" Singaporeans.
Nicolas Huang, a broad-shouldered half-German boy, completed basic training in early March.
Asked if he felt he received any particular treatment from officers, he smiles and says: "I've been in the Singapore system since I was born. They just call me 'ang moh' (white person), but it's all just for fun, no harm done."
The physical training is still tough - obese boys usually leave National Service as buff young men - but times have changed since the rudimentary years of the program.
In a concession to the much more comfortable modern lifestyle of Singaporeans, trainees get commercially catered food in Pulau Tekong. The mattresses in the bunks are thick and comfortable, and there's a television in the lounge.
The recruits are even asked to grade the canteen food in order to keep the caterers on their toes.
And for a generation raised on electronic video games, technology plays a key role in sharpening recruits' combat skills.
Before firing a real weapon in the rifle range, recruits use M-16 simulators in an air-conditioned room with a surround sound system, shooting at static or moving targets on a large video screen occupying the far wall.
The results are immediately flashed on the screen, and mistakes in body position, breathing technique and weapon angle are pointed out.
Commercially available computer games with combat themes are also modified for use by the military to complement live or simulated exercises. Even exercise routines like sit-ups and chin-ups are electronically tallied in a wired gymnasium to make sure recruits perform the minimum repetitions.
"Yes, the boys love it," Lieutenant Colonel Ng Wai Kit, head of the Singapore Army's training development branch, says of the widespread use of technology. "They are into it."