ROSSLEA, Northern Ireland — In an era of fading European boundaries, British soldiers are busy fortifying the Irish border against the "human bombs" of the IRA.
For months, an extra battalion of troops, engineers and civilian workers have been revamping the army's vulnerable network of checkpoints, which screen road traffic between the British-ruled north and the independent south.
The border forts have come under incessant bomb attacks from the Irish Republican Army.
In this soggy stretch of County Fermanagh, the border follows a twisting path and the IRA exploits its confusing contours, using the south as an arms dump and launching pad for operations against the British forces.
"The border constitutes a 300-mile difficulty. There are something like 300 crossings," says Brian Mawhinney, Northern Ireland's security minister.
The IRA has killed eight soldiers in three attacks on border posts in the past two years.
Last year, the IRA tried to destroy the Annaghmartin checkpoint in South Fermanagh using an 8,000-pound bomb, the largest ever seen in Northern Ireland. The elaborate scheme involved 20 gunmen, some of whom blocked traffic in the south while others held three households at gunpoint. They intended to force a Protestant farmer to drive an explosives-packed trailer across a field toward the base. The attack foundered when the trailer became mired in bog land within a few feet of the border.
The army's six already well-armored checkpoints in South Fermanagh are being outfitted with a varying combination of watchtowers, underground barracks, surveillance gear and remote-controlled gates. They will be covered by increased foot patrols in surrounding hills.
A key objective is to distance the troops' quarters from the road and checkpoint, so that huge bombs cannot threaten the bulk of soldiers housed in barracks there.
Lt. Gen. Sir John Wilsey, commander of the British army in Northern Ireland, says the checkpoints "are largely there for reassurance purposes. The isolated Protestant community living behind the border feel protected by knowing there's a thumping great building there blocking the road with soldiers in it."
Nationalist politicians and their Catholic constituents in border areas long have argued that the road checks are dangerous nuisances.
"Each of these static checkpoints is supposedly situated to protect the public against terrorism. But the great bulk of the British army's efforts is spent protecting the static checkpoint against terrorism," says Seamus Mallon, deputy leader of the Social Democratic and Labour Party.
The party, which represents most Catholic voters, wants to end British rule in Northern Ireland but rejects violence.
"Two things are certain," Mallon says. "No. 1, the people who are there, be they soldiers, policemen or the general public going through, are sitting ducks in the event of an attack on those checkpoints. And No. 2, the terrorists simply do not use the roads on which they are on, for their own nefarious reasons."
Soldiers along Fermanagh's front line--some newly armed with antitank rockets that protrude from the snouts of their submachine guns--seem edgy and aggressive, treating each motorist as a potential bomber.
When a stranger asked about the surrounding construction work, a lance corporal standing outside the Annaghmartin post joked: "I could tell you about it--but then I'm afraid I'd have to kill you."
An attempt to take a photograph of the nearby Killyvilly checkpoint resulted in a clatter of army boots, confiscated film, half an hour of questioning, and the warning: "This isn't hassle, mate. We just want to get out of here alive."
Most of the area's Irish Catholic residents bitterly resent the British presence, and some despairingly see the construction work as a sign that the "Brits" are digging in to stay.
Efforts by local Catholics to reopen secondary border crossings have been met determinedly by army engineers, who in places have left a cratered moonscape in place of pasture.
British and Irish authorities agree that combating IRA activity on the border will require broader cooperation between their two armies.
None of the 16 British posts is actually on the border. They sit one to five miles within Northern Ireland in an effort to put them out of range of IRA bullets and mortars fired from the south.
British ground forces are not allowed to operate on the southern side, despite British commanders who want the right of limited "hot pursuit."
In a situation typical of the status quo, on March 15 two British helicopters came under heavy machine-gun fire near Rosslea, but kept flying. The IRA claimed it fired more than 1,000 rounds from three tripod-mounted heavy guns positioned about a hundred yards across the border.
Last fall the IRA reportedly fired a SAM 7 anti-aircraft missile from the south at helicopters, the first use of its much-rumored gift from Libya. Whatever the weapon was, it missed.