Leadership involves the use of power, and, as Lord Acton famously warned, power corrupts. And yet leaders without power – the ability to cause others to do what we want – cannot lead, writes Joseph S. Nye, Jr.

When oil demand is fairly strong, as it is now and tends to be in early summer, the price will be set by the marginal production costs in US shale basins and Canadian tar sands, writes Anatole Kaletsky.

As a foundation, we align ourselves and our strategies to shared global goals. Equally, we push ourselves to adapt to a changing world and confront emerging challenges.

To the rest of the world, Clinton represents continuity, and Trump means dramatic change. Just how dramatic cannot be known, but the normal assumption that candidates play to their party’s core supporters during the primary season but then tack to the center for the general election cannot be relied on in Trump’s case, writes Bill Emmott.