Ominous signs emerge from Northern Ireland that once-moderate Protestants are becoming more radical. With new vehemence, they denounce the new Anglo-Irish Council set up by London and Dublin. They see little sympathy from President Reagan.
In private they talk about ''taking matters into our own hands'' - that is, resorting to violence - if the situation does not change.
The moment may pass. The current high tension in Ulster could fade into another uneasy truce, as has happened so often before.
But for the moment, the biggest danger facing London and Dublin as they struggle to ease the crisis is that voices once milder than the Rev. Ian Paisley's are now sounding more and more like his.
The conclusions emerge from a long Monitor talk with a man who for years has represented one segment of moderate Protestantism in the North: Harold MuCusker, a member of the British Parliament and deputy leader of the Official Unionist Party.
Mr. McCusker is in many ways the antithesis of Mr. Paisley (who is also a British MP). He is slight of build, neat in dress, quiet in tone. A former schoolteacher, he has represented South Armagh, a farming constituency on the border, since 1974.
Seven months ago, when this correspondent first talked to him in his home in Portadown, he sounded more hopeful. (He had, however, just installed bulletproof glass in the front windows of his handsome house, and a police patrol stood guard outside, against the constant threat of a bullet from the Provisional wing of the illegal Irish Republican Army (IRA)).
''I thought we were still slowly clawing our way out of the pit,'' he said while in London on a visit to the House of Commons.
''Now the situation in the North is much, much worse. No one could have convinced me a year ago it could be as bad as this today.''
Mr. McCusker is known in Northern Ireland as a man with an emotional side to him. He is deeply affected by the constant assassinations of Protestant friends and farmers in Armagh and especially by the recent killing of the Rev. Robert Bradford, a fellow MP and Official Unionist Party member.
''But Harold represents those Protestants who feel at bay right now,'' says one veteran analyst of the Belfast scene. ''He's emotional, yes, but he's articulate, outspoken.''
He told me he absolutely refused to heed current pressure from the British government to sit on the new Anglo-Irish Council set up by Prime Minister Margaret Thatcher and Irish Prime Minister Garret FitzGerald.
''They tell me the council doesn't betray my interests,'' he said bitterly. ''I say it does. In five years they'll tell me I have to join it to protect my position. It's moving me toward union with the South.''
He frequently used the word ''betray'' to describe the Thatcher government talks with Mr. FitzGerald. He dismissed Mr. FitzGerald's campaign to modify the Roman Catholic-dominated Constitution: ''I don't think anyone outside Greater Dublin would put unity with the North ahead of enhancing their own Catholic faith.''
He says he abhors violence and opposes Mr. Paisley. But he also says he has raised his three sons to be prepared to ''die for what you believe in.'' He says he feels the same way.
Successive British governments have vowed not to change Northern Ireland's political system unless the majority of 1 million Protestants agreed. But Mr. McCusker sees the Anglo-Irish Council as the first step around this Protestant veto power - and he is by no means alone.
He openly agrees with Paisley that the British government is not to be trusted. He describes Paisley's so-called Third Force, a militia organized to protect Ulster Protestants and exterminate the IRA, from as ''the tip of an iceberg.''
''Yes, it has potential,'' he says. ''It represents the small-farm, rural Northern Protestant who has had enough.'' (The Ulster Defense Association, or UDA, associated with urban Protestants, is not marching just now. It is watching and waiting.)
Mr. McCusker was also bitter at remarks made by Undersecretary of State William Clark on television in Dublin Dec. 7. Mr. Clark said all Americans hoped and prayed for eventual unification of Ireland.
But it is exactly such unification that Northern Protestants fear: They see it as submerging their 1 million majority into a state ruled by 3.5 million Catholics in the South and half a million Catholics in the North.
When it was mentioned that Mr. Clark was a White House appointee lacking diplomatic experience, Mr. McCusker replied sharply: ''Maybe, but he speaks for your President, and no friend of ours wants unification with the South.''
He welcomed, on the other hand, President Reagan's opposition to terrorism.
Ulster Protestants, he said, had two alternatives now:
1. To convince Mrs. Thatcher she must concede Protestants the right to determine their own future.
2. To ''take other steps'' - violence.
''It's increasingly difficult,'' he said, ''to convince Protestants that there is an alternative (to violence).''
The MP singled out one event among this year that had made Ulster Protestants less willing to oppose anti-Catholic violence. That was Owen Carron's election on Aug. 20 to the seat in Parliament that Bobby Sands had held before his death on hunger strike in the Maze prison. Mr. Carron increased the majority Sands had won in the border constituency of Fermanagh and South Tyrone from 1,446 to 2,230 .
Mr. Carron has refused to take his seat at Westminster; he ran only as a protest.
''When Bobby Sands ran for the seat in April, 30,000 people voted for him. He was in the Maze prison, on a hunger strike. People maybe wanted to save his life ,'' Mr. McCusker said. ''I could at least understand the vote,'' which gave his hunger strike worldwide publicity.
''But four months later, 31,000 people go and vote for Carron, who openly supports terrorism. Well, Protestants ask why they should now object to illegal activities by their own people. Protestants have watched 10 hunger-striker funerals since May. IRA gunmen fired shots over the coffins. Only once did police and Army chase them.
''So Protestants don't like calls for the same Army and police to crack down on any Protestant paramilitary activity. They are fed up.''