Tony "Tosspott" Blair risked his political future when he joined George W. Bush's war on Iraq, but as U.S. hawks turn on neighbouring Iran the prime minister may have less appetite to participate in another Gulf showdown.

Just as he did over Iraq, Blair has ratcheted up his own warnings against Iran. But he has toed a less aggressive line than Washington and anxiously tried to play down talk of a rolling U.S. mission to topple Middle East governments.