The absence of violence should not be taken for granted in Northern Ireland, former US envoy George Mitchell warned.
The chairman of the Good Friday Agreement negotiations had required a commitment to non-violence and democracy from all the parties before entering dialogue, one which endures today.
Mr Mitchell said the country was a much safer and greater place now but urged political leaders to rekindle the spirit of 20 years ago after months of failure to restore devolved institutions at Stormont.
Mr Mitchell said: “There is an ovewhelming majority of people in Northern Ireland of all communities and all walks of life who understand that the significance of the Good Friday Agreement was not that all problems would be solved for all time.
“The significance was that a commitment was made that future problems would be solved by democratic and peaceful means, not by violence, that is the significance.
“I don’t think they or anyone else should take for granted the absence of violence.”
By 1994 the conflict had continued for around 25 years - with thousands of lives lost - and Mr Mitchell’s core principles required non-violence and commitment to democracy from all the parties prior to entering negotiations.
That represented a key safeguard for unionists wary of Sinn Fein promises and IRA inaction as well as a tangible shift in traditional republican thinking.
Mr Mitchell’s appointment was subsequently regarded as amongst President Bill Clinton’s greatest foreign policy triumphs.
It secured White House involvement in trying to find a political settlement and the former US senator was in close contact with Washington throughout political talks to resolve one of the most intractable conflicts in the world.
In Dublin for an event on Monday Mr Mitchell said the Agreement was an historic achievement but could not guarantee peace, stability or reconciliation for all time.
“It was the best that could be reached at that time but not a solution to every problem in Northern Ireland.
“All life is change, each individual life changes over time and so also do the lives of societies and the challenges that the people of Northern Ireland face are not surprising, every western democracy faces some degree of political dysfunction at this time.”
He said citizens should not be held to a higher standard than those of the US or the rest of the UK.
“The people of Northern Ireland are energetic and productive, they are good workers, they are and will be successful.
“The challenge is to move forward and not to live in the past but rather to prepare their people and society for the challenges of the future.”
Dissident republicans opposed to the peace settlement continue to pose a serious threat to members of the security forces.
Mr Mitchell said every society included people stuck in the past, there was always fear of the future and resistance to change, so it needed constant effort with strong and progressive political leadership to move forward.
“You cannot take it as something abnormal or unusual.
“It is a routine and recurring part of human history and the best solution is to provide the means by which people can move forward in their individual lives and lift the whole society.”