Why foreign affairs sucks

One of the things which has been commented upon in discussion of Ming Campbell's fall as Lib Dem leader was the fact that before taking the top job, he'd been an accomplished foreign affairs spokesman. This is true, but possibly explains why Ming didn't exactly prove to be a successful leader. Foreign secretaries and spokespeople often tend to be lousy if they take over the top job. While all political careers usually end in failure, it seems foreign affairs is an especially poisoned chalice.
There are 13 people who have been both Foreign Secretary and Prime Minister, of whom 3 (Wellington, Salisbury and Ramsay MacDonald) combined the roles, with Salisbury the only one who had been Foreign Secretary before becoming PM. The first was Lord Grenville, about whom I know nothing. George Canning died shortly after becoming PM. Wellington was a far better soldier than he was Prime Minister. The others in the 19th century were Palmerston, Russell, Salisbury and Rosebery, all of whom I will grant had some measure of success.
However, it's when we get to the 20th century that things really turn bad. The six people who served as both Foreign Secretary and PM were Ramsay MacDonald, Anthony Eden, Harold MacMillan, Alec Douglas-Home, Jim Callaghan and John Major, of whom only MacMillan can be considered at least a halfway decent PM.
Things get even worse if we look at the list of Foreign Secretaries who have failed to lead their party or who have been a political disaster if they did so. Arthur Balfour, Austen Chamberlain (until William Hague the only Tory party leader not to become PM), Sir John Simon, Lord Halifax, Ernest Bevin, Herbert Morrison, Rab Butler, George Brown, Tony Crosland, David Owen, Lord Carrington, Francis Pym, Geoffrey Howe, Douglas Hurd, Malcolm Rifkind, Robin Cook, Jack Straw and Margaret Beckett - and that's not even a full list.
It's probably just as well for the Lib Dems that our current foreign affairs spokesman, Michael Moore, has been so anonymous in the role that nobody is even mentioning him as a possible party leader. I'd advise all Labour supporters to sell their shares in David Milliband now.