An average thriller with a sad assassin

I read this book on first publication in the early 90’s and I enjoyed but I must admit on this second reading it felt somewhat dated if not dull and formulaic.
It certainly has an explosive (literally) start with the brutal death of the wife and daughter of a quietly spoken man called Nguyen Ngoc Minh. We quickly learn that this seemingly mild-mannered owner of a Chinese restaurant is in fact a trained and lethal killer from a long forgotten war in the killing fields of Vietnam. He wants revenge for the senseless murder of his family and uses his battle skills and training to single handedly start a one man war against the IRA. We follow Nguyen on his sad quest knowing that whatever the outcome the journey will be bloody and violent and yet hoping that some kind of justice will prevail.

This book is actually advertised as the first in the Mike “joker” Cramer series....which is a bit of a joke in itself as our very own muscle bound SAS hero only appears as the story concludes. His jokes, testosterone and muscle bound attitude is therefore very limited and for that I am eternally grateful because the real hero in the book is Nguyen Ngoc Minh.....a simple man living a quiet life when everything he knows and loves is destroyed and this sets him off on a journey with just one question....why??