There is another, almost equally significant area in which Bush can be credited with seeing farther and more clearly than most of his contemporaries: that of energy. As President, Bush was excoriated by opponents at home and abroad for his early rejection of the Kyoto Protocol and then for the support he gave to companies wanting to prospect for oil in a protected area of Alaska. “Drill, baby, drill,” became the tedious catchphrase of his many adversaries.

By emphasising Bush’s supposed antipathy to environmental issues, however, those same adversaries neglected a strand of his domestic policy that warranted just as much, if not more, attention: his determination that the US should reduce its dependence on imported energy. Many ascribed the “drilling” aspect of Bush’s policies to what they saw as his profound distrust of environmentalism – although, in fact, his views were generally more progressive than those of mainstream America. Others saw the residue of his early career as a Texas oilman, and his continuing contacts with the industry.

There may be an element of truth in both. Probably the overriding consideration, however, was his belief that the US was constrained in its foreign policy, as in its economy, by its dependence on imported energy. Previous presidents, from Nixon on, had nurtured the same ambition – to make the US self-sufficient in energy – but Bush set about systematically trying to achieve that.