Could the United States Really Miss the Mobilisation?

Public political statements, allied intelligence contacts, Commonwealth links, and the visible assembly of roughly 150 ships made the mobilisation difficult to hide. American personnel worked inside joint headquarters at Portsmouth, Plymouth, and Gibraltar, while Canadian and New Zealand links created still more paths for information to travel. This does not mean Washington approved every operational detail. It does separate American foreknowledge from American willingness to support the operation once its political outcome became uncertain.