President Trump’s recent taunt that Keir Starmer is ‘no Churchill’ betrayed an attachment to the mythology of the Special Relationship. At its most effective, the relationship has rested on the careful cultivation of personal intimacy by prime ministers who understood that Britain’s leverage depended less on what she could offer than on what she might, at some cost, withhold. At its weakest, it has amounted to little more than sentimental theatre.

During the Suez Crisis 70 years ago, Britain discovered that she could no longer rely on the American alliance to simulate being a great power. What the post-Suez decades reveal is how successive prime ministers attempted precisely that simulation – and what it cost them. Britain tried to convert intimacy into influence; sometimes it worked tactically, but never structurally. Four postwar partnerships illustrate the pattern with clarity, each revealing a different strategy for managing the asymmetry that Suez laid bare, and its limits. It is in the moments of crisis – Cuba, the Falklands, Iraq, and now Iran – that the architecture of the alliance is tested, and the temper of the bond between president and prime minister is put to the proof.

Harold Macmillan and John F. Kennedy have entered historical folklore as the closest of Cold War partners. Macmillan, who had gone from ‘first in, first out’ at Suez to senior transatlantic statesman within five years, liked to cast Britain as Greece to America’s Rome: a civilisation offering memory and judgement to a youthful empire rich in power but short on historical sense. The metaphor was flattering, and it was also a trap. At the Nassau Conference in December 1962, when a question over access to Polaris missiles threatened to drive the two allies apart, Macmillan played his hand with calculated desperation: if Britain could not have Polaris, she would go it alone, and he would resign. Kennedy yielded because the alliance still carried strategic weight. Yet Macmillan’s broader policy of close interdependence was already failing. Britain was losing her empire while America was gaining its own, often at Britain’s expense. The personal bond had delivered a tactical success, but it could not arrest the structural reality: the relationship worked for Britain only so long as Britain retained something America needed. The Greeks, it turned out, were Rome’s dependants.

If Macmillan demonstrated what intimacy could purchase, Harold Wilson showed what it cost to refuse the price. Lyndon Johnson wanted British forces in Vietnam, not for their military value, but for the symbolism: ‘A platoon of bagpipes would be sufficient’, he remarked, ‘it was the British flag that was wanted.’ Wilson would not oblige. His refusal, compounded by Labour’s withdrawal from military commitments east of Suez, left Johnson contemptuous of a prime minister he regarded as an unreliable debtor. Yet the two pragmatists continued, however coldly, to maintain the transatlantic machinery. The alliance endured not because they admired one another, but because neither could afford to be seen dismantling it. Here, the Special Relationship revealed its institutional skeleton: stripped of warmth, it still functioned, sustained by intelligence-sharing, nuclear cooperation, and the diplomatic habit of consultation.

In the 1980s Margaret Thatcher grasped that mere maintenance was not enough, that an alliance which merely persisted, without yielding influence, served American interests more than British ones. She understood the transactional grammar of the alliance better than any postwar prime minister and saw that the machinery could be made to serve British interests, provided one operated it with conviction. She and President Ronald Reagan shared genuine ideological sympathy – smaller state, robust defence, instinctive anti-Communism – but she never mistook affinity for entitlement. During the Falklands, she secured US support by making plain that Britain would fight with or without Washington; Reagan calculated, correctly, that the longer-term alliance was worth more than a convenient relationship with Buenos Aires. At Reykjavik, the Iron Lady went further: intervening to reshape an American nuclear proposal that she judged reckless for European security. Thatcher could shape American decisions because she retained the credibility of a leader prepared to act without American permission. She proved that the alliance yielded most when Britain needed it least.

Tony Blair drew the opposite conclusion. Convinced that the alliance must be maintained at almost any cost, he attached himself first to President Bill Clinton, with whom he shared a doctrine of liberal intervention and ‘international community’, and then to George W. Bush, with whom he shared rather less. The bombing of Serbia followed from the first partnership; Iraq from the second. Where Wilson’s defiance had preserved British autonomy at the cost of American goodwill, Blair’s compliance purchased goodwill at the cost of autonomy and of public trust at home. The domestic consequences still shadow Labour’s foreign policy. Blair understood the Churchillian bargain – nuclear access, intelligence-sharing, economic weight – and judged that Britain’s seat at the top table required her to be, above all, a dependable ally. In Iraq, dependability shaded into acquiescence. The accommodation ran in one direction, and the independent judgement that had given Thatcher her leverage was precisely what Blair surrendered.

The current occupant of No 10 Downing Street does not share his Labour predecessor’s reading of international law, nor his appetite for intervention. In this, he is closer to Wilson than to Blair. Britain’s nuclear deterrent, her intelligence apparatus, and her permanent seat on the UN Security Council still furnish the transactional basis of the alliance. But these are inherited assets, not renewable ones, and their diplomatic currency depreciates with each decade of diminishing British capacity. The present crisis over Iran, in which Britain has signalled caution on escalation, without severing cooperation on intelligence, logistics and regional defence, echoes Wilson’s Vietnam refusal more than Thatcher’s Falklands assertion, an act of restraint born less of strategic confidence than of straitened circumstances.

Whether Starmer can navigate the present crisis without either the personal rapport that Macmillan cultivated or the independent weight that Thatcher commanded remains to be seen. The problem for Starmer is that he inherits the language of a ‘strategic partnership’, but not the surplus that once made that language credible. The post-Suez decades suggest that the Special Relationship, such as it is, rewards those who bring something to it beyond goodwill or rhetoric – and that access to the White House, however priceless, carries an expiry date for a country that no longer maintains the power to justify it.