Gen John de Chastelain is the best known member of the Independent International Co mmission on Decommissioning. As its chairman, his reputation is on the line.
The 64-year-old retired soldier and diplomat has been involved in the North's peace process since 1995, when he became one of the three-man international body on arms decommissioning. In 1996 he was appointed one of the international chairmen who oversaw the talks that led to the signing of the Belfast Agreement.
Before the agreement was signed, he received an overlapping appointment in 1997 to chair the International Commission on Decommissioning and has been a steady presence in a tortuous process to put paramilitary weapons beyond use.
Alfred John Gardyne Drummon de Chastelain was born in Bucharest, Romania, in 1937 to an American mother, Marion Walsh, and a Scottish father, Gardyne de Chastelain, both of whom were involved in high-level espionage during the second World War.
He was educated in England and Scotland before moving to Canada in 1955, where he became a career army officer. He held the rank of lieutenant commander at the age of 32. He served with NATO and with the UN forces before becoming chief-of-staff of the Canadian armed forces from 1989 until December 1995, with a one-year period in between as Canadian ambassador to the US.
He is married with a son and daughter and a number of grandchildren.
The most recently appointed member of the decommissioning commission, Mr Andrew Sens is no stranger to delicate political negotiations.
A former US career diplomat, he was part of the task force involved in negotiating the release of US hostages in Iran when student activists seized the Tehran embassy in November 1979.
A career that started in 1966 in the US embassy in Kampala, Uganda, took him to Bordeaux as consul, and to Washington as a trade negotiator and energy-policy specialist. He also served in Oslo, Tehran, Islamabad and Buenos Aires.
Following his retirement from the diplomatic corps, he was appointed to the staff of the decommissioning body. Some 19 months later he was appointed a member of the body's committee.
He is married to Ms Sharon Visscher and they have a son.
Before his appointment to the international decommissioning commission in 1997, Brig Gen Tauno Nieminen's most recent experience of conflict was as head of a border-monitoring mission between the Federal Republic of Yugoslavia and Bosnia-Herzegovina.
That was in 1995 and followed 30 years in the Finnish military. Born in July 1942, he became a soldier in 1962 and graduated from the country's military academy three years later. For the next six years he was based in Helsinki where he was a battalion commander.
He subsequently held assignments on the general staff of the military defence forces and the Helsinki military headquarters. In the 1970s he served in the UN force in Cyprus as a company commander and operations officer.
A military academic, he studied at Finland's war college and attended the US army college in Fort Leavenworth, Kansas, in the early 1980s. He returned to the US in 1988 as a visiting scholar at Harvard University. He retired from active service in the Finnish military in 1992.
Brig Gen Nieminen is married with two daughters.