Heart-wrenching pictures and television images of thin, fresh-faced children in fatigues, toting real rifles and trying to look older than their age might soon be a thing of the past.

Capping a decade of international efforts to fight a major cause of human rights violation, a treaty to ban the use of child soldiers comes into force today.

A United Nations Treaty called the Optional Protocol to the Convention on the Involvement of Children in Armed Conflict establishes that no one under the age of 18 shall be compulsorily recruited into the ranks of armed forces.

The decision will touch the lives of nearly half a million minors worldwide.

The Protocol also imposes an obligation that governments and states must raise the minimum age for voluntary recruitment to at least 16 years. In addition countries who are party to the Protocol must ensure that members of their armed forces under 18 years of age do not take a direct part in hostilities.

US and Britain violating the treaty?

So far the Optional Protocol, adopted in May 2000, has been signed by 94 countries, with just 14 having ratified the treaty. Though the most blatant cases of child conscription are found in Africa and Asia, the phenomenon is also found in the Americas and Europe.

But the first signs of discrepancy are already beginning to show. Human right activists are lashing out at two world powers, America and Britain, signatories of the Protocol for weakening the treaty by insisting on recruiting youths under 18 into their armed forces.

The US ambivalent on recruitment

Rory Mungoven, coordinator of the Coalition to Stop the Use of Child Soldiers said London and Washington had played a key role in ensuring that the 18-year rule did not apply across the board when the pact was approved after long negotiations in 2000.

Before that the US for six years had vigorously opposed the minimum age for participation in armed conflict as 18.

Today the US is one of a number of states that will enlist volunteers at 17.

Mungoven believes that the US is taking advantage of the fact that it is difficult to draw the distinction between voluntary and forced recruitment. "The US say it is alright for us to recruit because we will do it responsibly. But there has to be one standard for all", he said.

Britain along with Belgium, Canada, India and Australia allow young people to join their armed forces at 16, though they are bound by their treaty obligations to do their utmost to keep them away from any fighting.

No more excuses

The United Nations High Commissioner for Human Rights, Mary Robinson, said her office is "urging all governments and armed groups to end the military recruitment of children under 18 and to release and rehabilitate those children already in service".

"There can no longer be any excuses for using children for war", she added.

Mind-numbing statistics

The non-governmental Coalition to Stop the Use of Child Soldiers estimates that up to half a million minors serve in governmental, paramilitary and other kinds of armed forces in 85 countries around the world.

Of those, more than 300,000 children, mostly between 15 and 17 but some as young as ten are believed to be involved in active combat in armed conflicts in some 40 different countries around the world, from the guerilla struggles in Colombia to the bloody civil wars in Africa.

Child soldiers recently took centre stage in a major conflict when the US and Britain fought along side Northern Alliance forces against the Taliban. Both sides counted children among their ranks – victims of a society numbed to war over two decades of it.

The UNICEF estimates that more than 2 million children have been killed in armed conflicts in the past decade, four to five million disabled and 12 million left homeless.

Scarred for life

If the sheer numbers and statistics are numbing, the variety of roles that these children fulfill during war according to the UNICEF, are even more shocking. Many of the children are kidnapped or forced into military service.

Guerilla armies and governments use the young boys and girls as cooks, messengers, sex slaves, spies and front line fighters. Apart from the physical dangers of armed combat, where losing limbs or one of the senses is common, children are easy victims of psychological and emotional trauma.

But monitoring the Protocol will not be an easy task for officials. The problem is compounded especially in poor African countries where the lure of food and money is hard to resist for a starving child.

"Children are cheap, obedient and can be easily brainwashed to commit extreme acts of violence," says Rory Mungovan.