"It's time for the IRA to go out of business. And it's time for Sinn Fein to be able to say that explicitly, without ambiguity, without ambivalence, that criminality will not be tolerated," Mitchell Reiss told BBC radio in Belfast in a telephone interview from Washington.
Reiss specifically chided Sinn Fein leader Gerry Adams for his remarks during his speech Saturday to the party's annual conference.
Adams, reflecting traditional IRA-Sinn Fein policy, claimed the movement wouldn't tolerate criminals in its ranks. He immediately qualified that position, arguing that the IRA wasn't committing crimes when it broke laws "in pursuit of legitimate political objectives."
Analysts say that view justifies virtually all of the IRA's current activities, including its robberies, fuel smuggling and policy of maiming petty criminals in the IRA's Catholic power bases.
Reiss said he found that comment "particularly worrisome. ... You can't sign up for the rule of law a la carte."
Reiss' remarks followed an IRA statement Tuesday in which the outlawed group said it had offered to kill four men, including two recently expelled IRA members, who have been blamed for the slaying of 33-year-old Robert McCartney outside a Belfast pub Jan. 30.
The killing has focused public attention on the refusal of the Sinn Fein-IRA movement to accept the Police Service of Northern Ireland, a major unfulfilled goal of the 1998 peace accord for this British territory.
Detectives trying to bring charges against McCartney's killers say they know who did it, but require testimony from some of the approximately 70 witnesses to the attack. Traditionally the IRA kills people who inform on IRA activities to police.
The Bush administration, in a departure from the policy introduced by former President Bill Clinton in 1995, has decided not to invite Sinn Fein or other Northern Ireland political leaders to this year's St. Patrick's Day celebrations March 17 at the White House. Sinn Fein also has been excluded from the U.S. House of Representatives' traditional St. Patrick's luncheon.
Reiss confirmed Tuesday that McCartney's five sisters — who have waged a public campaign over the past month against IRA intimidation of witnesses — will be among Bush's guests. He said the White House this year plans to invite a range of grass roots figures from Northern Ireland who are promoting compromise between the province's British Protestant majority and Irish Catholic minority.