Members of the DUP team have become veterans of protracted talks, often negotiating with opponents who have literally tried to murder them .
EU officials involved in negotiating the Northern Ireland backstop admitted afterwards that they couldn’t believe the British had signed up to it. “We knew it would not be acceptable to the unionists,” one said.
Months on, that message still seems to be struggling to get through in Westminster. Is it really so hard to understand why those whose entire existence is founded on preserving the Union between Great Britain and Northern Ireland would stand firm against a proposal which, in their eyes, fatally threatens it?