A Belfast street during the Troubles (Picture: PA).
Any return to a hard border in Northern Ireland would be a "political failure" by both the British government and the European Union, a former head of the Army has said.
General Lord Richard Dannatt was commissioned into The Green Howards regiment in 1971 and served in Northern Ireland. He received the Military Cross at the age of 22.
His comments come days after reports that Brexit talks have run into a "significant problem" over the issue of the Northern Ireland border.
EU negotiators are said to be demanding a "backstop to the backstop" to prevent a return of a "hard border" between the North and the Irish Republic.
Prime Minister Theresa May has insisted that any backstop must be time-limited, but the Irish government has already ruled this out.
Asked by the Press Association if he was concerned that a hard border could result in a return to the Troubles, Gen Dannatt said: "I don't want to see a return to a hard border.
"It would be a political failure by our own Government and by the European Union 27 if that was to be the case.
"Over 650 British servicemen lost their lives over the 38-year campaign to produce the much more harmonious society that there is in Northern Ireland now.
"I don't want to see politics bringing a regression and the return to bloodshed.
"I don't think it will happen, I don't want it to happen, it would be a disaster if it did happen, it must not happen."
The Prime Minister has insisted an exit agreement is still "achievable" despite negotiations stalling just days ahead of a crunch summit in Brussels on Wednesday.