Donald Trump’s imminent return to the White House is prompting the inevitable pronouncements about its wider significance for the United States: for American institutions, its global leadership and prospects for domestic renewal.

But all the speculation cannot possibly predict how Trump deals with the circumstances which await him following inauguration. So vast and all-consuming have been the changes to the world since he left office in January 2021 that the briefing books foreign governments retained from the first Trump presidency offer only the patchiest guide.