When Northern Ireland exploded into widespread sectarian violence last month, Catholics trying to leave this border village ran up against burning barricades manned by militant, masked members of the Protestant Orange Order.
For nearly five days, few people were able to get in or out. Even garbage trucks from the large neighboring town of Strabane had to be rerouted via tiny roads through the Irish Republic.
The burning barricades are gone, but now in Castlederg - whose 3,000 residents are said to be, per capita, the most bombed in Northern Ireland - a cold war is brewing.
It is here that nationalist Catholics have revived an old weapon: the boycott. It was first deployed by Irish peasants against a British landlord named Capt. Charles Cunningham Boycott in 1880. Today, in Castlederg, a boycott is cutting deep into at least eight Protestant businesses.
"Nothing like this has ever happened to me [before]," says Victor Lecky, a local grocer who has seen his trade plunge by 25 percent since he received an anonymous letter informing him of the boycott three weeks ago.
The identical letters received by Mr. Lecky and at least seven other Protestant businessmen accuse the recipients of being among the chief instigators of the roadblocks and of thus condoning "the intimidation directed against innocent Catholics throughout the province."
Catholics in Castlederg may have endured Protestant thuggery, the letter continues, but are "still accorded the dignity of some rights, including the right to choose where we shop." The letter is signed: "Yours disappointed."
Derek Hussey, an active member of the Protestant Orange Order and local counselor for the Ulster Unionist Party, thinks the letters were not merely the work of one disgruntled individual.
"There has obviously been some sort of orchestration on the nationalist side of the community because the effect of this letter was almost immediate," he says. "As soon as the businesspeople received the letter, they noticed that a large percentage of their Catholic customers were no longer using their businesses."
Up the road, in a largely Catholic housing development, local Sinn Fein politician Charlie McHugh denies any orchestration of the boycott from his side.
Mr. McHugh concedes that local Catholics may be playing it safe by avoiding Protestant businesses. He says he has received calls from Catholics worried they might face retaliation from their own side if they're seen patronizing the "wrong" shops.
Castlederg residents are skittish about commenting on the boycott. One Protestant woman, emerging from a butcher's shop, said quietly that Catholics "have been told where not to shop, or they'll be dealt with."
But a Catholic housewife down the street demurred. "I haven't changed where I shop," she said, adding, "Mind you, near where I live most of the shops are Catholic."
Cross-community workers, such as Tanya Gallagher at Londonderry's Peace and Reconciliation Group, are concerned that the Castlederg boycott demonstrates a hardening of attitudes among both Catholics and Protestants.
It's OK to "challenge these businesspeople about their behavior," Ms. Gallagher says. "But surely there are other pragmatic ways of dealing with hurts than trying to hurt back."
What distresses the targeted Protestant businessmen of Castlederg is that, to a man, they deny any involvement in last month's roadblocks.
"It's so vindictive," says pharmacist James Johnston, who claims he visited the barricades only once to deliver prescriptions to a nursing home. "There are so many rumors going around, including that I was wearing an orange sash. I'm not even an Orangeman."
Grocer Victor Lecky expresses similar dismay. "It's not just the financial impact, although that's bad enough. It's ... the defaming that's going on," he says.
Sinn Fein's McHugh smiles thinly at such sentiments and talks of collective guilt. "I think it would go very far in stretching the imagination to believe that there was no Protestant businessman involved in any blockade in Castlederg at any level," he says, adding that he thinks the boycott eventually will fizzle out.
Prominent Castlederg unionists such as Mr. Hussey, however, see this boycott as a continuation of the effort to drive them out of Northern Ireland.