He joined the BBC as a reporter in Norwich in 1962 as a 24 year old, following his graduation from King's College, Cambridge with a first-class honours degree. He moved to London three years later, beginning a distinguished career as a foreign affairs correspondent with his first assignment in Ghana. Over the next 30 years he covered 11 conflicts and reported from 80 countries, making his name with coverage of the war in Vietnam, and also covering wars in the Middle East, Nigeria, Angola and Rwanda, as well as making many reports on the Troubles in Northern Ireland.
He won the Royal Television Society's Reporter of the Year award in 1977 and 1993, and was awarded the Order of the British Empire in 1992.
While covering the war in Bosnia he was seriously wounded by shrapnel while recording a report. What he saw while covering this war awoke a sense of injustice which was to influence his future career.
In 1997, just 24 days before the British General Election he announced that he was leaving the BBC to stand as an Independent candidate in the Tatton constituency in Cheshire, one of the safest Conservative seats in the country where the sitting Conservative Member of Parliament, Neil Hamilton, was embroiled in "sleaze" allegations. The Labour and Liberal Democrat Parties withdrew their candidates in Bell's favour, and Bell won with a majority of 11,000 votes becoming the first successful Independent candidate since the Second World War.
Bell was noted as an extremely effective constituency MP -- while not often speaking in the House of Commons (and when he did, mostly on matters of British policy in the former Yugoslavia and the third world), he very ably represented his constituency. Although urged by large numbers of people in Tatton to stand again in the 2001 General Election, he had promised in the 1997 campaign that he would only represent Tatton for one term. He was however persuaded to stand as an Independent candidate in the Essex constituency of Epping and Ongar where the sitting Conservative MP was also the subject of some controversy, but Bell was not successful in the 2001 election. He then announced his retirement from politics, saying that "winning one and losing one is not a bad record for an amateur".
He now acts as an ambassador for UNICEF and as a critic on the state of journalism today, although he describes himself as "too old" for both journalism and politics.