As any parent will tell you, great care is needed when issuing an ultimatum. If failure to finish your brussels sprouts is threatened to bring on an absence of dessert, then there is no point in the parent subsequently giving in and the child being allowed to indulge in jelly and custard. It may indeed bring about a modicum of family peace at the dinner table, but in the longer term it will be ruinous. For what will make the child eat his or her sprouts the next time they are served? Far better to have avoided issuing the ultimatum in the first place.
So it is in Northern Ireland. Despite having failed to finish their sprouts, the DUP and Sinn Fein are now tucking in to the jelly and custard. Meanwhile the anxious parents/prime ministers look like indecisive idiots. And how do they twist Northern Irish arms the next time?