The government says that the existing service, answerable to the cabinet secretary in London, can be the obedient servant of whatever combination of parties happens to rule in Westminster, Cardiff or Edinburgh.
This has already been inscribed in White House lore as a magnificent victory, snatched in the spring of this year from the mouth of defeat by a combination of presidential fortitude and congressional ingenuity (or stubbornness and rule-bending, as Republicans see it).