the so-called "Real IRA" had gone full tilt with the aim of ruining the Good Friday Agreement and not stopped after the horrible carnage of the Omagh bombing?
Not likely. It would merely drive home what the DUP was saying at the time (they've changed their tune now) and securing their electoral dominance over the UUP.
After 911 most of their US funding dries up as the US cracks down on terrorist finances and holdings, regardless of whether its for the RIRA or AQ.