It was reassuring yesterday to hear Nigel Dodds, the DUP deputy leader, keep the focus on Sinn Fein.
It is tempting for unionists to succumb to a sense of the seemingly inevitable: that if Sinn Fein cannot be in power, Stormont falls.
That has been the position. At no point since 1998 has Sinn Fein faced specific sanction.
When the IRA spied at Stormont and broke into Castlereagh, all parties suffered the suspension of the Executive.
When the IRA raided the Northern Bank and some of its members murdered Robert McCartney, all Northern Ireland parties were disinvited from St Patrick’s Day at the White House, not just the IRA’s political wing.
Unionists have had to accept the Sinn Fein-must-always-be-included doctrine because of the implicit threat of direct rule with a green tinge.
Imagine the position was reversed, and it was made clear to nationalists that a unionist party had to be included, regardless of criminality or flagrant breaches of democratic norms.
And imagine it was Dublin that was implying to nationalists that they would face a more Orange form of government if they failed to go along with it.
Such a scenario is inconceivable, yet the reverse has happened.
But some things are aligning in Northern Ireland politics.
First, the flaws in the system of permanent rainbow coalition with no opposition are becoming harder to ignore.
Second, the leeway period long granted to Sinn Fein given its heritage is coming to an end. The party and its associates will have to behave as would a governing party in Sweden or Australia or Canada.
And these trends are happening when a standalone Conservative government will hold power until at least 2020.
David Cameron and Theresa Villiers (who has been far from outspoken in the current crisis) will at some stage in this parliament have to address the intrinsic problems in the Stormont arrangements. This crisis is the opportunity to set that process in motion.