Russia's friendship with Iran is warmer than ever these days, as the two countries fight side by side in Syria. Today Hassan Rouhani, Iran’s president, meets Vladimir Putin in Moscow to discuss the future. Trade and energy deals are on the table, as well as proposed sales of a reported $10bn-worth of Russian arms, including tanks, artillery and aircraft. Mr Putin values Iran as part of his strategy to make Russia a power-broker in the Middle East; Mr Rouhani nonetheless worries that Russia might sacrifice the relationship for a grand bargain with America. Perhaps the two men can bond over suppressing dissent: on Sunday thousands of demonstrators turned out in cities across Russia to protest against corruption.