The beauty of recycling China's surplus into metals instead of US bonds is that it kills so many birds with one stone: it stops the yuan rising, without provoking complaints of currency manipulation by Washington; metals are easily stored in warehouses, unlike oil; the holdings are likely to rise in value over time since the earth's crust is gradually depleting its accessible ores. Above all, such a policy safeguards China's industrial revolution, while the West may one day face a supply crisis.