T hey came for the afternoon tea and got the best of British in every sense. The US State Visit began with an intimate spread for 650 at the embassy in Washington . They got delicacies from all parts of the UK, Scottish smoked salmon, West Country cheddar, scones, clotted cream, the works. But they also got the reassuring presence of HM King and Queen in a week when it’s never been more needed . After the shooting at the Whitehall Correspondents dinner there were questions about whether the visit should be cancelled or postponed. Not in a million years. It is at times of uncertainty or anxiety that we need certainty more than ever. There is no one better to provide that. Time moves differently around the Royals; people walk slower; everything feels more measured and calm. In my last stint in the civil service I quite often found myself in the quiet rooms and corridors of Buckingham Palace.…