Jack Higgins: Angel of Death (UK 1996)

From the Publisher:
When a terrorist group called January 30, made up of leading members of the Establishment, begins wreaking havoc apparently at random, Brigadier Charles Ferguson is given special powers by the British Prime Minister to co-ordinate the fight against them.

Jack Higgins: Angel of Death. Signet, ISBN: 0451184297 (May, 1996), 273 p., £5.99.

Jack Higgins: Angel of Death (USA 1996)

From the Publisher:
They call themselves "January 30", after the date of a British massacre in Belfast. They are allied with no one, killing American diplomats and KGB agents, Arabs and Israelis, IRA gunmen and Loyalist soldiers. But they are definitely the enemies of peace--and they are plotting an assassination that will shatter an uneasy truce that reigns in Ireland.

Former IRA enforcer Sean Dillon must hunt down January 30 before they kill again. Before they spark another war. Before Dillon himself falls prey to the ultimate assassin--the Angel of Death...

Jack Higgins: Angel of Death. Berkley Publishing Group, ISBN: 0425152235 (March, 1996), 352 p., $7.99.