Caryl Churchill’s new play is like an explosive capsule, left on the stage to undermine our state of well-being. It also makes you feel helpless, limp with outrage and beset with insignificance. It is just 45 minutes long, but it contains a cosmology of experience in the fractious love affair between two men who run the world.

One is American, the other is British. One is Sam, as in Uncle, the other Jack, as in Union. They speak in unfinished sentences of several words each. They are suspended in space on a sofa, which rises higher with their acceleration of plans and policies. Sam is an important government official. Jack, whom he met in a bar and can hardly remember, is a family man, torn between domestic loyalty and the ultimate dependency that the surge of power and protection brings.

Theirs is, indeed, “a special relationship,” which thrives on intervention and aggressive intent. The word “democracy” is never mentioned. Nor are “moral values” or the idea that the coalition of interests is in some way representative of decency, freedom or civilisation. There is, of course, “a threat to our security.” If the writing were less clever than it is it would be easy, therefore, to say the piece merely reiterated a common perception of American foreign policy, supported by a cowed and fawning Britain, being an unthinking, power-crazy force for evil. You may conclude that Caryl Churchill retains this view, and that the Royal Court is an accomplice to her opinion. But this would mean that her writing lacks the impact of dramatic metaphor and true theatrical expression.

It doesn’t, of course. But I will admit that, after seeing the play, I read the script twice before coming to my conclusions. Like A Number, her last play about a parental relationship and the cloning of children, the play is dense, fast, elliptical, superficially baffling and finally rewarding. No other writer can achieve what Churchill now does, which is to convey a universe of feeling in a minimal, stripped back artistry. Though completely dissimilar to Beckett and Pinter, she is surely now in their class in this respect. Only one speech extends beyond two lines, that of Sam – when Jack has temporarily abandoned him – about the techniques of torture.

The catalogue of intervention is relentless and dizzying: the scare tactics in Chile and Nicaragua, the blocking of elections all over the place, the storage of nuclear weapons in seven European countries, the indiscriminate use of chemical weapons and cluster bombs, the official collusion in drug-running operations and vote-rigging. The towers have been destroyed but Saddam is not yet destabilised. The best is yet to come.

James Macdonald’s production is a model of fast-paced clarity and concentration and the design – the stage is lit around its proscenium frame with innumerable light bulbs – is the work of Eugene Lee, whose other current London show is Wicked, a quite different sort of paean to American culture and politics. Ty Burrell, an American actor with a history of Churchill credits, is faultlessly smooth and dynamic as Sam, while Stephen Dillane’s Jack of all trades catches exactly a sense of confusion overtaken by excitement.

- Michael Coveney