{"record":{"aliases":[],"appointmentIds":["canada-e2a1b592517adf"],"appointmentsDataset":"https://chanceries.org/diplomats.json","archivalSources":[],"canonicalUrl":"https://chanceries.org/diplopedia/people/john-de-chastelain-b5fb3bed41/","countrySlug":"canada","entityId":"https://chanceries.org/diplopedia/people/john-de-chastelain-b5fb3bed41/#person","eventIds":[],"expandedParagraphs":["John de Chastelain was born in Romania, educated in Scotland, and moved to Canada at eighteen. After graduating from the Royal Military College, he pursued an army career that took him to the rank of general. He served as Canada’s ambassador in Washington in 1993–1994, then returned to military leadership as chief of the defence staff.","In late 1995, the British and Irish governments asked him to work with George Mitchell and Harri Holkeri on the problem of paramilitary weapons in Northern Ireland. Their international body recommended that political talks and disarmament proceed together. De Chastelain went on to chair the Independent International Commission on Decommissioning, helping turn negotiated principles into procedures for putting weapons beyond use. His commission witnessed IRA acts of decommissioning in 2001 and 2002, although renewed political deadlock interrupted progress."],"id":"canada:john de chastelain","identifiers":{},"legacyPersonIds":[],"legacyUrl":"https://chanceries.org/diplomat-b5fb3bed41b8645fecec.html","name":"John de Chastelain","notes":[],"paragraphSources":[["cain-bio"],["cain-bio"]],"profileUrl":"diplomat-b5fb3bed41b8645fecec.html","relatedEvents":[],"relatedPeople":[],"relationships":[],"researchStatus":"reviewed","reviewedOn":"2026-10-28","revision":"6514cf2084e272a3","sources":[{"accessedOn":"2026-10-28","date":"","id":"cain-bio","locator":"Biography by Brendan Lynn, paragraphs 1–7","publisher":"Ulster University, CAIN","title":"John de Chastelain — Biographies of People Prominent During the Troubles","type":"scholarship","url":"https://cain.ulster.ac.uk/biography/DeChasteralin_John_1999.html"},{"accessedOn":"","date":"","id":"mission-f0bbba56ac699e42f2ac","locator":"","publisher":"","title":"John de Chastelain — mission record (1993–1994)","type":"Mission record","url":"https://w05.international.gc.ca/CHOMA-CDMCE/Posting/View/2379"},{"accessedOn":"","date":"Accessed 21 October 2026","id":"mission-3c9e89462afdcdc1960d","locator":"Tenure chronology; pre-1989 appointments belong to earlier chancery buildings.","publisher":"","title":"Canadian ambassadors to the United States: roster","type":"Mission record","url":"https://en.wikipedia.org/wiki/List_of_ambassadors_of_Canada_to_the_United_States"},{"accessedOn":"","date":"","id":"mission-2bbe87e5bfe41593dba6","locator":"","publisher":"","title":"John de Chastelain — mission record (1993–1994)","type":"Mission record","url":"https://www.canada.ca/en/news/archive/2014/11/order-canada-investiture-ceremony.html"}],"topics":["Northern Ireland peace process","arms decommissioning","military diplomacy"]},"schemaVersion":1}