If someone really is prepared to remove X from a contract then X gets crossed out.
But if that person spends weeks and weeks resisting X’s removal, then it’s there for a reason. Even if that person says they’re not really that serious about X. If X stays in despite numerous attempts to get X out, then it’s there to be used if required.
The UK government is kidding itself if it thinks it can just declare it can get out of the backstop.
But it suits the EU totally. Tying us up in years of legal quagmire. Just what they want.
Update: The Telegraph:
Theresa May and Jean-Claude Juncker agree to ‘legally binding’ assurances on Irish backstop
Shorter version: They’re not legally binding.