Ordered by Emperor Hadrian in AD 122, Hadrian's Wall marked the north-western frontier of an empire whose armies had crossed continents. It was not an impregnable barrier, nor was it meant to be. Its gates regulated movement, its forts economised on soldiers, and its stone line imposed order on an exposed frontier. It was, above all, an admission rendered in masonry: even Rome had limits.
The most revealing walls in history are not always those erected by the weak against the strong. Sometimes they are the boundaries that power is eventually compelled to draw around itself.
Vietnam taught the United States a related lesson. At the height of the war, more than half a million American troops were deployed there. The United States possessed overwhelming advantages in aircraft, firepower, communications and logistics. Yet material superiority could not convert an ill-defined political purpose into a sustainable victory.
Vietnam did not destroy American power. It exposed the distance between the capacity to destroy and the capacity to decide political outcomes. An adversary did not need to match the United States weapon for weapon. It needed to endure, deny Washington a decisive conclusion and make the price of continuation exceed the value Americans attached to the objective.
That distinction matters again today.
American power is immense, but it is not self-executing. A carrier group requires fuel, maintenance, munitions and replenishment. Aircraft require overflight rights, tankers, runways and spare parts. Distant forces require ports, communications, intelligence, pre-positioned supplies and politically dependable hosts. The United States itself acknowledges this. Its defence strategy speaks of building infrastructure, logistics, access, dispersal and mobilisation with allies. Before it can fight abroad, it must first get to the fight and remain supplied there.
This is not evidence of weakness. Every great power relies on networks. It is evidence that American primacy is partly a coalition achievement, sustained by thousands of permissions that are usually mistaken for permanent facts.
The same is true of financial power. The Federal Reserve reports that the dollar still represented 56.42 per cent of disclosed official reserves in Q4-2025, about half of international payments and majorities of international banking claims and liabilities. No rival currency currently combines, at the dollar’s scale, full convertibility, deep funding and payment networks, and a single vast pool of liquid government securities. But the legal and political confidence sustaining those advantages can no longer be taken for granted.
Dominance, on the other hand, is not invulnerability. A reserve currency is a network of confidence before it is an instrument of coercion. Its strength depends on other states choosing to hold it, banks choosing to clear through it, and traders choosing to invoice in it. A coalition need not overthrow the dollar to limit the reach of financial coercion. It can diversify reserves, widen local-currency settlement, build supplementary payment channels and reduce dependence at the margin. Each step may be modest. Taken together, they create an exit option — and every credible exit option changes the balance of a relationship.
This is where a simple act of bravery becomes politically consequential. One ally may decline automatic access. A court may insist that emergency power is still subject to law. A central bank may diversify prudently. None of these acts can defeat a superpower. Together, they can remind it that consent is not obedience and partnership is not subordination.
The language of authoritarianism also needs greater precision. American institutions have often applied the term to Arab states. But authoritarianism should not be treated as a geography, still less as an Arab cultural condition. Arab governments, whatever their constitutional form, are rarely unconstrained. They negotiate among ruling families, militaries, tribes, commercial interests, religious authorities, fiscal realities, public expectations and external pressures.
The United States has the opposite problem: an elaborate constitutional architecture of Congress, courts, federalism, elections and a free press, but safeguards on paper operate only when people are willing to use them. In 2026, V-Dem recorded the largest annual decline in American liberal democracy in its historical series, attributing much of it to diminished media freedom, weakened congressional accountability and pressure on institutional independence.
America’s greatest danger, then, is not a coalition strong enough to conquer it. It is the belief that no coalition could inconvenience it, no ally would withhold cooperation, no institution would resist, and no alternative network could emerge. That belief turns advantage into overreach and partnership into resentment. It also invites the very balancing behaviour it seeks to prevent.
This argument is not anti-American. On the contrary, it appeals to America’s own constitutional wisdom: power must answer to power. Checks and balances were never designed to flatter authority; they were designed to frustrate it when necessary. Allies can perform a similar function internationally — not as enemies, but as custodians of a partnership that must retain consent to retain legitimacy.
Hadrian understood what empires repeatedly forget: survival sometimes requires a boundary. The United States does not need humiliation, and the world does not need its collapse. It needs an America recalled to proportion — by its institutions, by its allies and, where necessary, by the quiet accumulation of alternatives.
All that may begin with a simple act of bravery: saying no, until law, consent and purpose prevail.
Ahmed al Mukhaini
The writer is a policy analyst
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