"In light of yesterday's developments, the chief constable and I have decided that a further reduction in security profile is possible," said Lieutenant-General Sir Reddy Watt, the officer commanding Northern Ireland, on Friday.
"I can announce that preliminary work is starting today in south Armagh on the removal of the hilltop observation tower at Sugerloaf Hill near Camlough, on the vacation and closure of the base at Forkhill and on the removal of a super-sangar at Newtownhamilton police station," he said. The super-sangar is a lookout post.
A more general revised security programme was also expected to be published soon, while plans were being made to allow on-the-run paramilitaries to return home, according to news reports.
Belfast, Dublin and London, however, were awaiting the first reciprocal proof from the Roman Catholic paramilitary group of its commitment on Thursday to ending more than 30 years of armed struggle.
In addition, the swift response by the British Army at a base in south Armagh, on the border with the Republic of Ireland, sparked anger among some Protestants.
Members of the main Protestant Democratic Unionist Party (DUP), headed by the veteran Ian Paisley, were furious at the speedy reaction by the British Army, which still has 10,500 troops in the region.
"It's criminally irresponsible of the government to do that, given what has gone on in those border areas," said Arlene Foster, a senior DUP member.
"The government seems quite happy to act on words alone," she said.
"It's startling that, when the IRA give a statement saying they will stop what they should never have been doing, that the government acts so soon."
In contrast, a House of Commons lawmaker for Sinn Fein, the main Catholic party headed by Gerry Adams and the political wing of the IRA, welcomed the action.
"The start made today must be built upon in the days and weeks ahead, not just in South Armagh but across the six counties," said Conor Murphy.
"The demilitarisation of communities is an important element in consolidating the progress already made and ensuring that we build a new future free from conflict and division."
The IRA move was welcomed around the world, with the European Union joining the chorus on Friday.
The EU's foreign policy chief, Javier Solana, who was in Laos, called it a "historic event".