An excellent column from Martin Wolf about fighting the currency wars with stubborn China. China has become the nation with largest current account surplus in the world. It amassed more than $2.5tn reserves which are growing at $300bn per year. The impact on other high income countries, notably US, who are net importers of capital is devastating. Major economies are running large trade deficits with China leading to monetary policies heavily influenced by China’s currency trends. This situation, as Martin Wolf explains, is not sustainable. The only way to avoid a trade war, yet impose a currency restriction on China is to have capital control reciprocity. G20 countries must ask China to either stop buying their financial liability instruments or let other countries purchase China’s financial instruments.