Former Bank of England deputy governor Jon Cunliffe warns that U.S. allies are concerned about potential weaponization of the dollar-based payment systems by the Trump administration. Western countries heavily rely on U.S. banks, Visa, and Mastercard, with recent actions raising fears similar to the "kill switch" concerns in military hardware. Cunliffe notes that while U.S. policymakers may preserve dollar swap lines to avoid financial turmoil, a sudden loss of global confidence in the dollar could trigger a crisis resembling emerging market currency collapses.