“How can the weather ever be boring?” asks the hero of David Haig’s fascinating play. Admittedly the character is a meteorologist but he has a point: other countries have a climate whereas we in Britain have weather. But finally catching up with Haig’s much-travelled play, first seen in Edinburgh in 2014, I was struck by how it expands to acquire meanings beyond its immediate subject.
Haig has seized on the historical fact that there was much tension surrounding the timing of the D-day landings in Normandy in June 1944. General Eisenhower, in charge of European operations, had set a precise date of 5 June. However, James Stagg, chief meteorological adviser to the allies, arrives at the HQ at Southwick, Hampshire, and warns of severe weather conditions on the appointed day. If he is right, the invasion will be a disaster leading to massive loss of life. But he is vehemently opposed by his American counterpart, Colonel Krick, and Eisenhower is left to make the crucial decision as to whether to delay the operation.
Since we know the outcome, you might say there is little tension. Haig, however, gets round that in several ways. One is by giving us detailed information about the shifting weather patterns in the Atlantic so we begin to grasp the dilemma faced by Eisenhower.
Haig also sets up a contrast in character and method between the rival meteorologists. Krick relies on analogue charts recalling weather patterns in previous years; Stagg, a tenacious, hard-headed Scot, bases his forecasts on hourly scientific readings and precise knowledge of the complexity of British weather.
Haig constantly reminds us what is at stake but his play transcends its context. Given that the story involves Britain and the European mainland – though, in this case invasion rather than withdrawal – the conflict between a self-deluding optimism and a pragmatic realism takes on an unexpected resonance. I was even reminded of the debate about climate change, where wilful denial is confronted by inescapable fact.
Haig seems reluctant to bring his play to an end and overstresses the coincidental pressure on Stagg, whose wife is due to give birth even as D-day is imminent, but he has found rich drama in the interaction of war and weather.
As an actor, he is also ideally equipped to play Stagg. Haig’s forte is playing men in the grip of an idee fixe: in farce that can be very funny but here it means he endows Stagg, head always thrust forward in a state of permanent inquiry, with a peculiar brusque intensity. Even if Stagg’s worries about his wife occasionally intrude, Haig also makes something deeply moving out of the moment when the character’s quivering anxiety breaks through his surface stoicism.
Malcolm Sinclair is exemplary as Eisenhower showing how the poker-backed professional soldier is awed by his sense of responsibility. Laura Rogers also tactfully suggests the thwarted adoration of Ike’s driver, Kay Summersby, for her boss and John Dove’s finely calibrated production boasts good support from Philip Cairns as the Pollyanna-like Krick and David Killick as a garrulous electrician. It may be a traditional play but it is one where, as so often, history acquires the power of metaphor.
• Until 1 September. Box office: 020-7395 5405.