We know Arlene Foster has no great attachment to the Good Friday Agreement.
She famously split from the Ulster Unionist Party on the issue and threw in her lot with the DUP, which strenuously and vociferously opposed the deal.
We also know that the agreement has been subject to change, most notably at St Andrews in 2006, which resulted in the DUP agreeing to share power with Sinn Féin.
However, the core principles of the Good Friday Agreement, which was passed by the majority of people on both sides of the border, remain in place and cannot be abandoned or unpicked at the whim of a unionist leader.
Mrs Foster knows this but she is unable to disguise her exasperation at how the agreement is being invoked in the Brexit negotiations.
She told the Daily Telegraph: ''It has been deeply frustrating to hear people who voted Remain and in Europe talk about Northern Ireland as though we can't touch the Belfast Agreement. Things evolve, even in the EU context.''
The DUP leader's comments drew a swift and critical response, with both Taoiseach Leo Varadkar and Tanaiste Simon Coveney speaking out in defence of the agreement.
Sinn Féin president Mary Lou McDonald branded Mrs Foster's comments 'dangerous' and 'unacceptable' while UUP leader Robin Swann said she was potentially undermining the consent principle which he said was 'sacrosanct'.
There will be no real surprise at the embattled DUP leader seeking to muddy the waters in terms of the Good Friday Agreement.
The fact that it is being used as a major weapon by the EU is plainly a source of considerable irritation.
Mrs Foster, fresh from her latest appearance before the RHI inquiry, is undoubtedly enjoying the rather more favourable attention she is receiving at the Tory conference, with her views being sought on Brexit as well as Boris Johnson, whose leadership ambitions have been on full display.
There is obviously a lot of political jockeying going on and the DUP leader's comments on the GFA will be viewed in that context.
