I am of an age where I remember watching on TV news armed British troops walking through Northern Irish towns - eyes alert and weapons at the ready.
These were tense times with the soldiers considered by many locals as the symbol of hated British rule.
Places such as Belfast were fiercely split between Catholics and Protestants, with riots and tensions galore on the streets.
71 takes us back to, as you might imagine, 1971.
A British regiment is sent over to Belfast to help the local police keep order and root out any undesirables.
We concentrate on one particular private, Gary Hook (played by Jack O’Connell) for whom this is a first assignment.
But as soon as they go out to the Falls Road area all hell breaks loose as a riot breaks out and Hook is left abandoned.
At this stage in Irish history the Catholic section was seeing factions within its own ranks with younger more extreme elements emerging.
So Hook ends up being chased by very intense IRA members, intent on killing him.
But, with the complicated politics within the community and even the army, he is also targeted by others.
O’Connell is superb and is quickly building an amazing CV, including last year’s Starred Up which was another gritty drama.
This movie requires a good range of emotions as Hook is under extreme emotional and physical pressure.
Director Yann Demange has a long TV career behind him but his move to the big screen is impressive.
He doesn’t let the action drop and this is certainly not a film to relax to, with much of it filmed at night and in the shadows.
There are some great performances to back O’Connell up, including Sean Harris who plays an army captain working undercover and living on the edge of the law.
The film throws up all manner of questions about the conflict and the use of the army.
But the strong message that comes across is that the innocent all too often end up suffering the most.
Plus we are left in no doubt that violence is not glamorous, it’s unpleasant and traumatic.
71 is well worth a watch, but the 15 certificate is for some very extreme language and realistic bloody scenes that will shock some people.
Film details: 71 (15) 99mins
Director: Yann Demange
Starring: Jack O’Connell, Sam Reid, Sean Harris
Screening courtesy of Horsham Capitol