treaty has been widely ratified. , 173 states had ratified or acceded to the treaty; a further seven states had signed but not yet ratified it (Haiti, Iran, Lebanon, Liberia, Nauru, Somalia, and Zambia). In addition, following OPAC's adoption the number of states restricting enlistment to adults aged over 18 has increased substantially, according to Child Soldiers International: from 83 in 2001 to 126 in 2016, which is 71 percent of countries with armed forces. These include several states where child recruitment had been routine, including Colombia and Sierra Leone. Approximately 60 non-state armed groups have also entered agreements to stop or scale back their use of children. Despite this trend, Child Soldiers International reports that the recruitment of children for military purposes remains widespread, including by armed forces in the three most populous countries – China, India and the United States – and the most economically powerful (all G7 countries apart from Italy and Japan). A large number of non-state armed groups also recruit and use children routinely, especially following a recent surge in child recruitment by militant Islamist movements in Africa and the Middle East, as well as by militias opposing them. 'OPAC turns 18': 18th Anniversary event, 2018 On 21 February 2018 a meeting was held at the UN to mark the treaty's 18th anniversary. The meeting, co-sponsored by Child Soldiers International, UNICEF, and the governments of Belgium, Canada, Colombia, France and Sierra Leone, was attended by approximately 100 delegates. The Special Representative of the UN Secretary-General for Children and Armed Conflict, Virginia Gamba, reported on the progress made and still to be achieved since the treaty was adopted: We have really come a long way. Today, 18 years later, we should celebrate the quantifiable progress accomplished. The issue of children and armed conflict has been squarely placed on the international peace and security agenda. Since 2000, at least 130,000 child soldiers were released due to the collective efforts of child protection actors. Thousands more were spared the ordeal of recruitment and use – because their country has joined OPAC and put in place measures to protect them. Making sure all boys and girls released and their communities have access to meaningful reintegration – to help them overcome the harrowing experiences they have been through – is essential. But this remains a huge challenge. Provisions of the OPAC treaty Main obligations The main obligations of the OPAC