Shia Iran and the Sunni Taliban are not natural allies, they came close to war in 1998, but they are likely to work together against America if pressed. An American or Israeli strike on Iranian nuclear facilities would facilitate their rapprochement as Tehran seeks vulnerable openings. Senior Italian officials, with some 4,000 troops on a 300 mile long border frontier with Iran outside Herat, have told me they are horrified at the idea of a war with Iran and would immediately need substantial reinforcement.