In the late summer of 1956, as Britain’s imperial presence continued its slow contraction, the Suez Canal still occupied a peculiar place in the minds of politicians and mandarins in Whitehall. Much of the old imperial structure had already fallen away; what remained was a loose system of bases, agreements, transit rights and diplomatic understandings. When the Egyptian leader, Colonel Gamal Abdel Nasser, announced in Alexandria on 26 July that the canal would be nationalised, he struck at the fiction that the canal could be treated as imperial routine.

In London, the announcement produced irritation as much as surprise, a sense that Nasser had failed to observe the customary limits of international conduct. For the Prime Minister, Anthony Eden, the canal was one of the few remaining expressions of British leverage in a world whose idiom was increasingly American. The crisis that now began forced a question that Britain had largely succeeded in postponing since 1945: what became of British foreign policy when a vital national interest encountered an American agenda that did not recognise it as such?

The Anglo-American relationship in which Eden had been formed took shape in the circumstances of 1940 and the pressures of wartime coalition. It rested on common enemies, shared intelligence and an established habit of conferences, cables and personal contact. In the postwar years, the Foreign Office often treated closeness to Washington as a measure of Britain’s standing in the world, as though the frequency of consultation itself implied equality of position.

Suez marked the point at which these habits began to fail. When London looked to Washington for support, the United States withheld endorsement and moved to block the course Britain had chosen.

For much of the intervening 70 years, the Suez Crisis has been treated as a morality tale about secrecy, deception and the theatricality of Anglo-French-Israeli collusion. Eden’s decision to conspire, and then to lie about it in Parliament, has provided a convenient centre of gravity.

Yet Suez was much more than a failed operation; it was the first sustained encounter between two assumptions that had coexisted, largely untested, since 1940. The British assumption held that the Anglo-American alliance was not only necessary for survival but sufficient to sustain Britain’s continued status as a great power. For Americans, partnership with Britain did not imply endorsement of Britain’s inherited place in the world. As the 5th Marquess of Salisbury remarked, ‘their idea of an alliance is so different from ours’.

The language British leaders used to describe the relationship hinted at this imbalance. The historically minded Winston Churchill, and later the more philosophical Harold Macmillan, liked to picture the United States as a youthful Rome, rich in power but short on historical sense, and Britain as a latter-day Greece, offering memory, political judgement and civilisational poise. By the mid-1950s, however, President Eisenhower, like the country he now led, no longer looked to Britain for instruction, and Macmillan’s metaphor survived only in its darker implication: it was in her powerlessness that Britain was soon shown to be Greek in a new Roman world.

The Soviet Union supplied a common horizon of danger for both Britain and America: nuclear questions required constant consultation, intelligence cooperation deepened, and each side was dependent upon the other. Britain required American power, and America required allies capable of lending legitimacy to an expanding global presence.

Beneath this working partnership ran a current of unease. In Whitehall, the old fear of American isolationism never disappeared. Memories of interwar withdrawal lingered, joined now by a newer anxiety about American volatility. The Republican victory of 1952 did little to reassure British observers. British diplomats, in their conversations in smoke-filled Pall Mall rooms, began to describe the Americans as mercurial, inclined to swing between extremes.

The British response to this perceived instability rested on Churchill’s conception of a ‘Grand Alliance’. A senior official gave the sentiment its bluntest expression when he remarked that Britain’s task was to ‘induce in the Americans something of that historical sense which they so sadly lacked’. These assumptions proved serviceable in the shared management of Soviet power. They proved far less reliable when questions of empire intruded.

Eden shared Churchill’s attachment to Britain’s imperial inheritance. So did much of the governing class. In the early 1950s, few British policymakers spoke as though they were presiding over a terminal enterprise, and the language of decline had not yet acquired the force of inevitability. In the United States, hostility to colonial rule ran deeper. Political culture and civic ideology, forged in revolt against monarchy, fostered an instinctive discomfort with European empires.

Eisenhower was not a doctrinaire anti-imperialist. He recognised that sudden withdrawals could release violent nationalism and open space for Communist exploitation. His preference for gradual transition, however, did not translate into any willingness to be publicly associated with the preservation of European influence. Eden understood that Washington wished to avoid this identification with British and French interests. What he did not fully grasp until 1956 was how far the United States was prepared to translate that preference into aggressive policy. He came to regard American behaviour as infused with an ‘exaggerated moralism, at least in areas where American interests were not directly engaged.’

The British presence, in the Americans’ eyes, appeared as a relic of Victorian domination and gunboat diplomacy. The truth was that by the 1950s Britain’s position in the Middle East rested on arrangements. Eden understood this structure as necessary to secure oil supplies and to prevent the strategic collapse of western interests. By the mid-1950s Europe derived most of its oil from the Middle East (about 80 per cent), a dependence that sharpened Eden’s conviction that agreements, once made, could not be broken with impunity.

From No. 10’s perspective, American policy displayed a troubling simplicity. In seeking to avoid the stigma of imperialism, Washington undervalued the stabilising function that British influence continued to perform. The result was a weakening of the western position. Not that British Middle Eastern policy was without faults; it could be reactive, improvised and constrained by inherited commitments. Eden was troubled by the growing sense that British freedom of action was being compressed by the constant need to accommodate US sensitivities, even in cases where American material interests were secondary.

Increasingly, the two countries appeared to speak past one another. Americans detected in Britain a tone of superiority rooted in class and tradition. Britons saw in Americans a tone of self-righteousness, born of a shallow historical sense and a fervent nationalism. Britain’s dependence on Middle Eastern oil, Eden remarked to his Cabinet in October 1955, was greater than America’s. So was British experience of the region. Policy, therefore, should be framed in accordance with British interests, and American support sought where it could be obtained. Suez would reveal how far that aspiration could be realised.

Both Britain and the United States shared a broad objective in the Middle East: the exclusion of Soviet influence. For Britain, the region remained a central theatre of national power. Egypt, the Suez Canal and the surrounding network of bases and agreements formed part of a larger structure through which London sought to preserve political weight and military reach. For Washington, the overriding concern was to prevent Communist penetration. Otherwise, the area did not yet occupy the commanding position it would assume in later decades; it helped that American investment in the Canal Company was slight.

When Nasser consolidated power in 1954, American officials tended to interpret the new regime as a potential partner. They feared that visible association with British influence would alienate Arab opinion and drive Egypt towards Moscow, hoping instead to draw them into the western orbit. Britain’s Foreign Office doubted that Nasser sought alignment with either camp and saw instead a politician driven by regional ambition and intent on unsettling the existing balance of power. Washington mistook Nasser’s independence for pliability.

American policy remained narrowly Cold War in character, treating the region as a strategic chessboard. Tensions sharpened in 1956 when Nasser recognised the government of Chairman Mao. Within weeks, Washington withdrew support for the Egyptian government’s Aswan High Dam project. This myopic decision, intended as pressure, had the opposite effect and furnished Nasser with both motive and justification to seize the Canal. By that point, Britain and the United States in important respects had begun to pursue competing designs in the same region.

Eisenhower’s Anglophilia was carefully bounded by an alertness to American interests and to appearances. He avoided displays of excessive intimacy with London and understood that the age of exclusive wartime partnerships had passed. Visible association with Britain and France, he knew, carried political costs in Asia, Africa and at the United Nations.

Eden never doubted Eisenhower’s goodwill. He did, however, overestimate its practical consequences. Unlike Churchill, who had struggled to reconcile himself to Britain’s reduced position, Eden had largely accepted the reality of a junior partnership. What he did not accept was that junior status implied the loss of freedom in matters London defined as vital. Cooperation with America was indeed desirable where possible, but, where British interests diverged, the country retained the right to act. In this assumption, Eden was mistaken.

That summer in Britain, beneath the surface of postwar exhaustion, there lay a residue of impatience. There was little appetite for meek acquiescence in the face of theatrical defiance by a colonel in dark glasses. The language of Gladstonian moral restraint and Little Englanderism, which had so often shaped British foreign policy, now receded. A harsher idiom resurfaced, Disraelian in tone, tinged with nostalgia for a time when Britain answered challenges rather than absorbed them. The Times declared that Nasser’s act was ‘a clear affront and threat to western interests, besides being a breach of undertakings which Egypt has freely given and renewed in recent years’. In the Commons, the crisis produced the most bitter divisions since Munich. The Labour leader, Hugh Gaitskell, who had initially signalled support for firmness, turned sharply against the government once Britain’s collusion with the French and Israelis became apparent; the Tory benches themselves were fractured, with several resignations and abstentions on the critical votes.

Within the Conservative Party this mood acquired an institutional form. The informal Suez Group, loose in structure but persistent in voice, opposed further retreat from Britain’s remaining Middle Eastern positions and regarded the canal as a line that ought not to be crossed. Eden did not belong to this world of unreconstructed imperialism. He was, however, sensitive to the political pressure it generated. He also showed little enthusiasm for a public debate conducted in legalistic terms and found lawyers to be a distraction.

The crisis itself unfolded in two movements. From late July into early autumn, Eden pursued diplomacy while quietly preparing for the possibility of force. He engaged with American proposals, tolerated international conferences, and accepted the slow choreography of multilateral process.

Delay carried its own penalties. Each additional week made it harder to construct a convincing case for intervention and a casus belli. Public opinion began to drift. Diplomatic avenues multiplied without producing resolution. Eden’s patience with the manoeuvring of the US Secretary of State, John Foster Dulles, thinned. Dulles appeared to offer process without commitment – conferences convened, proposals floated, timetables extended – while the practical effect was to drain momentum for any course that might embarrass Washington. Eden began to suspect that the machinery of consultation had become a device for postponement ad kalendas Graecas.

Eden rejected the charge that Britain’s position was colonial. Canal internationalisation, as he understood it, involved neither annexation nor conquest. He also believed that Britain was acting with Europe in mind as much as with itself. The canal was an artery for the continent and a collapse of British and French authority in Egypt threatened more than national prestige.

By October, the space for manoeuvre had narrowed to a blunt choice. Either Britain accepted Nasser’s seizure as irreversible, or it attempted to reverse it by force. Eden did not believe that a prime minister could explain to Parliament, still less to the country, that a vital interest had been abandoned because an ally objected. On 4 November, he told the US president that withdrawal would leave the Middle East in flames.

Collusion with France and Israel compounded an already perilous course. Secrecy disoriented diplomats; exclusion slowed military planning; the Israeli strike on Egypt appeared transparently staged to invite British-French intervention; most damaging of all, the scheme rested on the assumption that the United States would ultimately acquiesce. Washington’s response combined public reasonableness with private coercion. The pressure applied was financial, and a run on sterling exposed Britain’s vulnerability with brutal speed. Macmillan, who had earlier encouraged firmness, lost his nerve – he was ‘first in, first out’, in Harold Wilson’s phrase. Cabinet cohesion fractured and the operation stalled. A ceasefire followed; by late November, British forces were withdrawing. Suez did not end in battlefield defeat, since the British and French forces had achieved their immediate military objectives; rather, it ended in financial exhaustion. This was a modern form of constraint, quieter than force, but more decisive.

Both Eden and Macmillan had hoped that, even if Washington disagreed with their course of action, it would understand the motives behind it and preserve the relationship. For the United States the crisis was shaped above all by its standing in the Arab-Asian world, by the arithmetic of the United Nations, and by the proximity of a presidential election. British and French interests lay well down the list.

In January 1957, the re-elected president announced what became known as the Eisenhower Doctrine, offering American economic and military assistance to Middle Eastern states threatened by Communist aggression. The declaration was presented as a response to Soviet pressure. It also signalled something more consequential. The United States was now prepared, openly, to assume primary responsibility for the western position in a region where Britain and France had long been the principal external powers.

A question that had hovered over the crisis in London now received its answer. What American interests were served by the collapse of British and French authority? The United States would replace them.

The transition rested on a characteristic American assumption. By distancing itself from the language and imagery of European empire, Washington believed that newly independent states would gravitate towards American leadership. Eden later judged this belief a cardinal error: anti-colonial posture did not, in itself, generate strategic loyalty.

American policy after Suez pressed for unconditional British withdrawal and the abandonment of the whole approach that Eden represented. In this sense, the criticism directed at Eden is often curiously inverted. He is reproached not for misjudging American intentions, but for acting at all in a sphere where US opposition might have been expected. The premise that underlies this judgement is that British independence of action had already ceased to be legitimate. Eden had imagined an alliance grounded in partnership. He discovered that it rested on hierarchy.

The consequences in Britain were lasting. Within the Conservative Party, Suez discredited those who still believed in the recoverability of imperial power and the move towards decolonisation hastened. It also eased the way for a European turn that had previously sat uneasily within Britain’s global posture, even for politicians like the Europhile Eden. On the centre-left and among liberal intellectuals, a different shift took place. A form of moral internationalism gained ground, rooted in the belief that Britain might compensate for lost power by exemplary conduct and following international law. Leadership would be exercised through legalism and conscience rather than hard power and command. In time, this outlook blended easily with American rhetorical habits.

Up to Suez, there persisted a widespread sense, in both London and Washington, that the two countries had passed through an experience of exceptional intimacy during the Second World War. The memory of shared danger, combined command, and repeated personal contact among leaders fostered a lingering conviction that the Special Relationship possessed an almost organic depth. Disagreements would arise, as they always had, over trade, over China, over the handling of peripheral theatres. Such disputes were assumed to be secondary, little more than family quarrels.

To understand why Suez cut so deep, it helps to recall how shallow the foundations of the Anglo-American partnership had always been. The Special Relationship had always rested as much on sentiment as on structure. Its cultural origins lay in a late 19th-century Anglophile milieu that imagined a natural affinity between English-speaking peoples. That affinity was strained almost as soon as it was articulated. At Versailles in 1919-20, Americans and Britons clashed bitterly over reparations, colonies, and the shape of the postwar settlement. During the interwar years, a persistent American suspicion took hold that the United States had been drawn into the Great War for purposes not entirely its own. Naval rivalry and unresolved disputes over war debts further thinned goodwill.

Seen against this longer background, the wartime partnership of 1941-45 appears more provisional in nature. It was less the culmination of a steadily deepening friendship than a convergence born of utmost necessity. The Cold War supplied a new adhesive. Mutual security requirements sustained close cooperation, but they did not settle older differences about power, hierarchy and the ordering of the international system.

When Macmillan restored cordial relations with Eisenhower in Bermuda in March 1957, the repair was genuine. Something else, however, had been quietly surrendered: the belief that Britain could combine intimacy with Washington and freedom of action abroad had lost its plausibility.

Suez is often described as the moment Britain discovered that it was no longer a Great Power. A more precise formulation is that Britain discovered it could no longer rely on an alliance to simulate being one. Alliances do not erase asymmetry.