President Obama drinks a Guinness in Hayes Bar in Moneygall, County Offaly, during his visit to Ireland (Photo: Press Association)What one has always to remember, in speeches delivered abroad by statesmen from any democratic country—but especially from America—is that for them their most important audience is back home. President Obama’s performance in the medieval splendours of Westminster Hall, it seems, didn’t go down all that well back in the US of A: his meeting with the Cambridges got more media attention. Certainly, his oratory has often been more compelling; after the jokiness and rabble-rousing of a lot of his speech...