His third book, a short study of Charles Stewart Parnell published in 1980, challenged some of the arguments of the award-winning 1977 biography of Parnell by F. S. L. Lyons, though Lyons, one of the "doyens" of modern Irish history, acknowledged the younger historian's arguments by stating that "Nothing Dr Bew writes is without interest.

"[5] Bew's central thesis was that Parnell was a fundamentally conservative figure whose ultimate aim was to secure a continuing position of leadership for the Protestant gentry in a Home Rule Ireland.

[8] Bew was also involved in the Belfast Project, a Boston College initiative to record interviews with former participants in the Troubles, including former republican and loyalist paramilitaries.

[9] In 2014, Gerry Adams criticised Bew's handling of the Boston College project, as well as the journalist Ed Moloney and the former IRA volunteer Anthony McIntyre.

Bew was briefly a member of a group called the British and Irish Communist Organisation, which advocated the two nations theory of Northern Ireland.

[2] Trimble and Bew are both signatories to the statement of principles of the Henry Jackson Society,[15] which has been characterised as a neoconservative organisation.

[18] He was created Baron Bew, of Donegore in the County of Antrim on 26 March 2007,[19] and sits in the House of Lords as a crossbencher.