In 1985, the Irish government boycotted the St. Patrick’s Day parade in New York City, the biggest celebration in the Irish-American calendar. The cause of its umbrage was Peter T. King, that year’s grand marshal and someone the Irish government said was an “avowed” supporter of a terrorist organization, the Irish Republican Army.

King, then a local politician on Long Island, was one of the most zealous American defenders of the militant IRA and its campaign to drive the British out of Northern Ireland. He argued that IRA violence was an inevitable response to British repression and that the organization had to be understood in the context of a centuries-long struggle for independence.

“The British government is a murder machine,” King said. He described the IRA, which mastered the car bomb as an instrument of urban terror, as a “legitimate force.” And he compared Gerry Adams, the leader of Sinn Fein, the IRA’s political wing, to George Washington.

A quarter-century later, King is chairman of the powerful House Homeland Security Committee. In the wake of the Sept. 11, 2001, attacks on New York and Washington, he became an uncompromising supporter of the Bush administration’s counter-terrorism policies. And he has suggested that President Obama “use the word terrorism more often” so people understand the seriousness of his purpose.

As King prepares to hold hearings Thursday on what he called “the extent of the radicalization” of American Muslims, his past as a defender of armed struggle has led critics to assert he is imposing a double standard.

“My problem with him is the hypocrisy,” said Tom Parker, a counter-terrorism specialist at Amnesty International who was injured by an IRA bomb that struck a birthday party at a military hall in London in 1990. “If you say that terrorist violence is acceptable in one setting because you happen to agree with the cause, then you lose the authority to condemn it in another setting.”

“It’s ironic that someone who offered such vocal support for the IRA is involved in this kind of witch hunt against Muslims in America,” said Ibrahim Hooper, spokesman for the Council on American-Islamic Relations.

But King sees no parallel between the IRA and violent Islamist extremism, which he describes as a foreign enemy or a foreign-directed enemy. His preferred comparison for the IRA is with the African National Congress led by Nelson Mandela; the IRA, no less than the ANC’s military wing, was fighting for community rights and freedom, he says.

“I [wanted] a peace agreement, a working agreement, where the nationalist community would feel their rights would be respected,” King said in an interview at his Capitol Hill office. “I felt that the IRA, in the context of Irish history, and Sinn Fein were a legitimate force that had to be recognized and you wouldn’t have peace without them.

“Listen, I think I’m one of the people who brought about peace in Ireland.”

His interpretation of the past draws support from former president Bill Clinton and Tony Blair, who as British prime minister oversaw the most successful phase of the peace process in Northern Ireland. In the 1998 Good Friday Agreement, all parties to the conflict agreed to use “exclusively peaceful and democratic means” to pursue their aspirations.

“He had indeed been controversial (at least with the British!) in some of his earlier statements. But once he saw a path to peace that was just and deliverable, he urged and campaigned for everyone to take it,” Blair wrote in an e-mail. “I thought he was right in his concerns about the new global terrorism but could understand why he saw the Irish situation as different.”

Engaging ‘the Troubles’

Three of King’s grandparents came from Ireland, but apart from a great-uncle who fought for Irish independence in the early part of the last century, he was not from a family with any commitment to revolutionary politics in Ireland. When violence first broke out in Northern Ireland, King dismissed the IRA as “a bunch of crazy people.”

“The Troubles,” as they were called, erupted when Roman Catholics in the late 1960s began to demand equal treatment in employment, housing and education in the majority-Protestant province of Northern Ireland. Peaceful demonstrations were violently suppressed by local authorities, and the situation quickly escalated into open conflict, drawing in the British army.

The IRA was responsible for half of the more than 3,500 people killed in the ensuing 30-year conflict; of those killed by the IRA, about 600 were civilians, according to statistics compiled by researchers in Northern Ireland.

The group mortared the prime minister’s official residence at 10 Downing Street, bombed Harrods department store in London, and blew up a boat carrying the 79-year-old Lord Mountbatten, cousin of the queen and a daring World War II commander. The blast killed Mountbatten, two teenage boys and an 83-year-old woman.

King first visited Northern Ireland in 1980 when he accompanied fellow Republican Al D’Amato, who had just been elected to the Senate, on a fact-finding mission. King became a frequent visitor over the next decade.

He often stayed at the home of a senior IRA militant who ran operations in Belfast and was a welcome guest at the Felons Club, a heavily fortified drinking establishment for former IRA prisoners in West Belfast, according to Ed Moloney, author of “A Secret History of the IRA,” and a review of Irish and Irish-American press accounts of King’s trips.

King said the IRA commanded significant, if minority, support among Catholics. Its supporters in the community, he said, were “voting for war in their own back yard.”

“If civilians are killed in an attack on a military installation, it is certainly regrettable, but I will not morally blame the IRA for it,” King said in a 1985 interview with the Irish People, an Irish-American newspaper that backed the IRA.

King also was willing to engage the IRA’s enemies. He debated Unionists when they came to New York. During one trip to Belfast, he made a foray to the Shankill Road, a Protestant stronghold — a place where Irish-American Catholics were rarely seen — and met with a group of loyalist paramilitaries. King and the loyalists discussed the use of informers in special jury-less trials, which were employed by the British as a counter-terrorism tool against both republican and loyalist militants.

An infuriated Northern Irish judge threw him out of his courtroom, saying King was “an obvious collaborator with the IRA.”

King also clashed with prominent Irish Americans who condemned IRA violence. He dismissed the Friends of Ireland caucus in Congress, which included Sens. Daniel Patrick Moynihan and Edward M. Kennedy, as infused with a “moral arrogance and self-righteousness that would do justice to the royal family.”

‘Anchor’ in peace process

King was recently chosen to be chairman of the Friends of Ireland caucus he once ridiculed, the culmination of what might be called his own de-radicalization process.

King’s arrival in Congress in January 1993 coincided with a major shift in U.S. policy on Northern Ireland. President Clinton had promised during his campaign to support a visa for Sinn Fein leader Adams. And King was just about the only person in Washington who had a relationship with Adams.

Three days after his election to the House in November 1992, King was in Belfast for “a spiritual reawakening,” he told a Newsday reporter who accompanied him.

“It’s good to see you, Peter,” Adams said at Sinn Fein headquarters. “Would you have a cup of tea?”

Clinton said that King was “an anchor of America’s role in the Irish peace process.”

“He was one of the few Americans who knew and understood Adams,” Clinton said in an e-mail. “He helped to ensure Adams’s successful visit to the U.S. Capitol for a St. Patrick Day luncheon in 1995, where we shook hands for the very first time, a moment that represented the profound change in American policy.”

And King was grateful to the president for the breakthrough. He was one of only four Republicans who voted against all articles of impeachment charging Clinton with perjury, obstruction of justice and abuse of power.

King has described the fitful peace process, and his own role in it, in a barely fictionalized novel called “Deliver Us from Evil,” in which King is “Congressman Sean Cross,” the hero who helps stop a conspiracy to derail the peace process.

In one scene, over dinner at an Irish restaurant in Manhattan, Clinton and Cross reflect on whether it would have been possible to deal with the IRA after the Sept. 11 attacks:

“ ‘Sean, looking back on it, do you think I would have been able to move on Ireland the way I did if the World Trade Center had been attacked in 1991 instead of 2001?”

“No. And I’ve given that a lot of thought.”

“The terrorism aspect.”

“Yeah. There was such an outcry against terrorism after the Twin Towers, it would have been almost impossible to distinguish the IRA from al-Qaeda — even though to me there was no comparison.”

“It would have been very tough.”

In the wake of the Sept. 11 attacks, King cooled on Adams, Sinn Fein, and even Ireland because of what he perceived as a lack of support for the United States.

“We’ve not been that close over the last few years; I think they could have done more to stand by the U.S.,” King said of Sinn Fein. “I am disappointed. When things did go wrong for the IRA, when civilians were killed, I tried to put it in context, not defend it. But they weren’t doing that when it came to us in Iraq or Afghanistan.”

He hasn’t been to Ireland since the Sept. 11 attacks.

After Obama was elected president, King got a call from Rahm Emanuel, the incoming chief of staff. “President-elect Obama would like you to be ambassador to Ireland,” said Emanuel, according to King’s recollection of the conversation.

King said he thought hard about it over a long weekend, fantasizing about hosting his Irish relatives at the ambassador’s 62-acre estate inside Dublin’s Phoenix Park, where the Irish president also lives. But King declined the offer.

“I just felt I would be defending foreign policy I didn’t agree with,” said King, “and to be sitting there with a bunch of Europeans spouting anti-American stuff, I would have a hard time.”