King Lear, Act 2, scene 4:
Lear: No, you unnatural hags,
I will have such revenges on you both,
That all the world shall—I will do such things,—
What they are, yet I know not: but they shall be
The terrors of the earth.
This is very much the Trump style. I’ll cancel the Paris Agreement! Mexico will pay for the Wall!
Making credible threats is still an essential part of diplomacy. An Fengshan, spokesman for China’s policy-making Taiwan Affairs Office, said on 14 December :
Upholding the ‘one China’ principle is the political basis of developing China-US relations, and is the cornerstone of peace and stability in the Taiwan Strait. If this basis is interfered with or damaged then the healthy, stable development of China-US relations is out of the question, and peace and stability in the Taiwan Strait will be seriously impacted.
Major national interest? Check. Means to deliver on threat? Check. Careful wording allowing plenty of space for future escalation? Check. This threat is serious. Like this one.
You can also go wrong by being too specific. Theresa May, in her Brexit speech on January 17:
While I am sure a positive agreement can be reached – I am equally clear that no deal for Britain is better than a bad deal for Britain. Because we would still be able to trade with Europe. We would be free to strike trade deals across the world. And we would have the freedom to set the competitive tax rates and embrace the policies that would attract the world’s best companies and biggest investors to Britain. And – if we were excluded from accessing the Single Market – we would be free to change the basis of Britain’s economic model.
What had she been drinking?