Russian Prime Minister Vladimir Putin clearly fancies himself as something of an all-rounder. When not busy suppressing internal dissent or invading neighbouring countries, he likes to show off his softer side by having his photograph taken practising judo throws, fishing shirtless in Siberian rivers or shooting rare tigers. But Mr Putin is not quite as well-rounded as he thinks. When it comes to international finance, at least, his intellectual prowess is somewhat lacking. Speaking on Tuesday during Premier Wen Jiabao's visit to Moscow, Mr Putin said China and Russia should ditch the US dollar, and instead settle bilateral trade between the two countries either in rouble or yuan. He obviously thought he would get a sympathetic hearing from Mr Wen. After all, just last Friday a front-page article in the overseas edition of the official People's Daily lambasted the United States for having 'used the US dollar's hegemony to plunder the world's wealth'. Countries in Asia and Europe should get together and agree to use other currencies to settle international trade, the article suggested. Yet Mr Wen's response to Mr Putin's proposal was less than enthusiastic. Perhaps that's because he understands these things rather better than his Russian counterpart. If Mr Putin wants to trade in yuan he is barking up the wrong tree. Beijing's capital controls would make it extremely difficult for Russian companies to obtain yuan to pay for their imports from China. And there is little sign that Beijing is preparing to relax its restrictions. In fact it is tightening them. Of course, if China were to pay for its imports from Russia with yuan, then Russian companies could obtain the currency. But given that China ran a US$8.9 billion trade surplus with Russia last year, there wouldn't be enough yuan to go around. Denominating trade in the Chinese currency simply isn't feasible. More likely, Mr Putin meant China should embrace the rouble. The Russian currency is now fully convertible, so there is no particular reason why Chinese companies should not use it to pay for their imports from Russia. But neither is there any obvious reason why the Chinese would want to get paid in roubles for their exports. China's bilateral surplus means it would rapidly build up a sizable stock of roubles in its foreign exchange reserves. But rouble reserves aren't much good for anything. No other country wants to get paid in roubles, so they are no use for trading with anyone else. Nor are roubles a great store of value. Rouble bonds may carry a yield of 8 per cent, but with Russian inflation running at 15 per cent, that's a negative return in real terms. And as the charts below show, the rouble hasn't exactly been a star in the foreign exchange market recently, underperforming the US dollar both against the yuan (the first chart) and against a broader basket of currencies (the second chart). Mr Putin may find it unpalatable, but the truth is that countries trade in US dollars because it's convenient. Greenbacks are freely obtainable, and everyone accepts them as payment. What's more, essential raw materials and commoditised goods like computer chips are all priced in US dollars, which makes for transparency and simplicity. Anyone who chose to price comparable goods in another currency would effectively be shutting themselves out of the global market. That's why some 75 per cent of intra-Asian trade continues to be priced in US dollars. That will change eventually. But for the foreseeable future, countries are about as likely to abandon the US dollar as Mr Putin is to wrestle naked with a wild bear: the idea might sound interesting at first, but on consideration they are likely to think better of it.