Tyrwhitt's memorandum doubles as a diplomatic signal

The memorandum's appearance in Foreign Office records was part of its purpose because other powers could be told or shown Britain's rules. Although much of the text concerns Chinese hostile action and counter-piracy, the authority to protect British nationals applied to any dangerous circumstance. That broader clause quietly told commanding officers they could act against forces other than pirates when necessary. At the same time, the reporting requirements kept any use of force accountable to the commander-in-chief. The document combined diplomatic signaling and local initiative with an implicit promise that Tyrwhitt would back officers who acted within the rules.