There has been intermittent talk of crisis for months, maybe over a year – sparked by the IRA’s failure to disarm, by intermittent street violence (though seemingly on a more diffuse level than in past years’ massive confrontations), etc. It’s hard to gauge because NI politicians on both sides seem particularly fond of the “This is intolerable” school of public statements, meant to ratchet up the perception of crisis – even when the escalating crisis may be defused by orchestrated concessions on one side or the other, and the pronouncement of crisis seems meant more for (a) jockeying to get a better set of concessions and/or (b) reassuring the politicians’ power base.
Overall, as is amply covered elsewhere, the root of the current “crisis” seems to be Unionist dissatisfaction with the “unbalanced” outcomes of the Good Friday agt. – i.e., Republicans got out of jail (along with Loyalists), and got increasing roles in NI and North/South bodies, got some concessions on the RUC, whereas Unionists think they themselves gained nothing from Good Friday. They point to disarmament as a specific grievance, but seem generally peeved over a feeling that they are seeing their position unilaterally eroded (e.g., many Marching Season parades are re-routed, which is an unmitigated “victory” for Nationalists as twenty years ago the Orange Order could generally march where they wanted).
Both the Loyalist and Republican organizations and political allies, and the British Govt., are not strangers to strategically timing particular actions and highlighting particular initiatives or problems. The most obvioius example is the periodic paramilitary ceasefires or reductions in punishment beatings, etc., usually timed to prove “peaceful” bona fides. Who knows whether the U.K., who obviously wants to see Trimble keep his grip, thought that timing this announcement would pressure S.F. to grant additional concessions/disarmament moves, or otherwise allow Trimble breathing room with his power base?
From S.F.'s perspective, it has long been the reality that the Nationalist leadership has been drawn heavily from those with active Republican backgrounds – there have been some cute denials, but if pressed, they’d probably fall back on their baseline position that the Republicans are a legitimate army fighting a war against unjust occupation, and that IRA membership or military activity is not, in itself, condemnable (even in a politician). As far as I know, the I.R.A. has never stopped “targeting” or training or other behind the scenes activity, even during ceasefires, which can be perceived either as consistent with their claim to be a real and legitimate military operation (given that national armies do train during peacetime), or as a carrot-and-stick approach to remind the U.K./Loyalists that if Nationalists don’t get the concessions they want from peaceful/political negotiations, they’re ready and willing to go back to other means.