My United Provinces Stadtholder was somewhat puzzled to be greeted by King Karl XII of Sweden with the line 'Facing 20,000 of your friends, how can anyone be so lonely?' followed by a declaration of war. Being fond of 70's and 80's music he immediately identified this as a line from 'Supertrouper' by Swedish Popstars Abba! Is there nothing new under the sun?

Anyone else spotted any amusing diplomatic ripostes concealing subtle double-entendres of a humourous nature?