Everyone in Washington believes that financial sanctions on undesirable foreigners, with tough enforcement through the banking system, are an effective way to impose US power without spending money or sending troops. More to the point, from liberal Democrats to populist Republicans, they all think it sounds good on TV.

Despite the Trump administration’s deregulation push, the US government’s authority to impose sanctions has spread from Russians to the rest of the world via the Global Magnitsky Act. Not to mention the self-explanatory Countering America’s Adversaries through Sanctions Act (passed 98-2).

Consequently a great deal of thought is being dedicated to finding ways to avoid US power over dollars. Classic solutions (gold), techno-solutions (bitcoin etc) and plain old fake documentation have been stretched beyond their limits. Now sanctions evaders, resentful foreign officials and geeks are working on tweaks to the Chinese yuan.