AS HM King Charles III’s Coronation procession clatters, creaks, clanks and stamps its way from Buckingham Palace to Westminster Abbey and back on 6 May, the world will gaze at Great Britain PLC doing something at which it is still world-beating: looking magnificent on parade. But behind the gleam, the spit and the polish, and the endlessly rehearsed drills, there are other things going on. First and foremost, the pomp of the coronation procession is an ever-evolving, generations-old pageant staged by British monarchs to impress their subjects (although for ‘subjects’, now read global television and internet audiences), not only with their grandeur and wealth but also with the potency of their Armed Forces, who march alongside them. However, all those riding, marching and standing military personnel have their own mission:…