No, I am going to make some progress.
There are three elements to the improved deal on the backstop, and I want to go through all of those. The first is a joint instrument—not a further exchange of letters, but something with comparable legal weight to the withdrawal agreement. It provides a new, concrete, legally binding commitment that the EU cannot act with the intent of applying the backstop indefinitely. Doing so would breach the EU’s obligations under the withdrawal agreement and could be challenged through arbitration. Were the EU to be found in breach, the UK could ultimately choose to suspend the backstop altogether, with that suspension lasting unless and until the EU came into compliance with international law. In these circumstances, we could also take proportionate measures to suspend the payments of the financial settlement.
Just as important, the joint instrument gives a legal commitment that whatever replaces the backstop does not need to replicate it, providing it meets the underlying objectives of no hard border between Northern Ireland and Ireland.