In the feverish run-up to conflict, it is only natural that the protagonists should be on the hunt for ways to justify their rash actions. In the months preceding the 2003 Iraq War, that came in the form of the confected claims that Iraq had stockpiled weapons of mass destruction and trained Al-Qaeda operatives in how to use them.

With a fresh set of tariff barriers this week set to ramp up tensions between China and the United States, it's now coming in a different form: A narrative that compromises with Beijing on trade is impossible because it treats foreign investors and powers as vassals to be subdued.