(Photo by Niall Carson – Pool/Getty Images) Labour has had its bad moments, devaluation in 1949 under Clement Attlee, devaluation again in 1967 under Harold Wilson, and the International Monetary Fund crisis in 1976 under Jim Callaghan. But all those crises were largely beyond the control of government.  The unfolding war in Iran is a huge external shock, but the crisis that Keir Starmer finds himself in is both greater and more self-inflicted than these three black spots in Labour history. Unlike the earlier prime ministers, Starmer arrived in office with an underpowered cabinet and No 10 and without a plan, most significantly for growing the economy. Starmer and his Chancellor, Rachel Reeves, have failed to generate growth. For all that, changing the skipper is deeply perilous, even if the local elections are terrible. The bubble will get very excited about whoever Starmer’s successor is, but in truth they don’t matter very much. Starmer is hard-working, honourable and highly intelligent.…