In the UK, 16-year-olds cannot vote, drive a car or drink alcohol. But they can join the army, and this week two charities, Child Soldiers International and ForcesWatch, accused the Ministry of Defence of perpetuating the "outdated" practice of recruiting children into the forces.The charities argued that the government was wasting taxpayers' money – as much as £94m a year – recruiting 16-year-olds into the army. The MoD disputed the figure, instead arguing that under-18s joining the army enjoy a wide range of benefits, training and experiences.

But, beyond the arguments about costs, there is the fundamental issue of how children develop the desire to be soldiers? The army states that it doesn't recruit children under the age of 16 and that soldiers must be 18 before they can be deployed to the front line. However, it does host a section on its website called The Camouflage aimed specifically at 14 to 16-year-olds "looking for more info on army life", which offers a target-shooting game for children: "The SA80 is the standard issue rifle for all soldiers – so you'll need to become familiar with it."

"We don't go into schools to recruit," says Nick Richardson, the colonel in charge of recruiting at the MoD. "We only enter schools to support the curriculum and for awareness-raising. We advertise on TV and in cinemas, plus we have stands at careers fairs and milk rounds. Parents are engaged throughout and must sign a consent form." But allowing 16-year-olds to enlist means "[we] end up with some really good, focused soldiers. They serve longer – 8.8 years, on average – than those who enter aged 18 and over [5.1 years]."

Around 20% of new entrants into the army have been cadets at school, says Melanie Bowran, spokeswoman for the Army Cadet Force, which is "largely sponsored" by the army: "The cadets get to meet serving soldiers on a social, casual basis and attend summer camps. They will often be affiliated to a particular regiment. But we don't recruit. We never instigate it. If a cadet raises the subject and shows an interest we will simply hand them over to the army recruiters. The cadets began in the 1850s as a way to recruit soldiers, but it hasn't been that way for decades."

But on ARSSE (Army Rumour Service), which claims to be the "UK's largest and busiest UNofficial military website", there was support for 16-year-olds joining the army. "[It is] one of the last channels of social mobility for bright and reasonably fit youngsters from all strata of society," remarked "Brotherton Lad". "On balance, I think it's a good thing for the individuals, the army and society in the round."