JANET Yellen, the US treasury secretary, has finally acknowledged what has been obvious to most people for quite some time, namely that the imposition of sanctions against countries that the US is hostile to, runs the risk of jeopardising the hegemony of the dollar as the world’s reserve currency. If the sanctions were imposed on just one or two countries, then matters would be different; but sanctions these days are used by the US to target dozens of countries, and, when this happens, those countries tend to get together to form alternative arrangements for bypassing such sanctions.