Why the dream of a borderless world misunderstands what borders are for

The borderless world is one of modernity’s most seductive ideas. Tear down the barriers, let people and capital flow freely, and prosperity will follow as surely as water finds its level. It is an argument advanced with equal conviction by Silicon Valley libertarians and campus progressives, by Davos panellists and street protesters. And it is, in its purest form, wrong — not because openness is bad, but because the argument mistakes all borders for the same kind of thing.

There are, broadly, two kinds of border in the world. Call them the membrane and the wall. The distinction matters more than any slogan about tearing them down.

The wall needs no introduction

A wall is a non-cooperative border. It exists to exclude, to hoard, to punish movement. The Berlin Wall was a wall. The barriers that sealed off South African townships were walls. A wall says: what is mine stays mine, and what is yours stays out. Walls are instruments of zero-sum thinking. One side’s gain is the other’s loss. They are, in the language of game theory, the physical expression of a non-cooperative equilibrium — a Nash equilibrium in which every actor, pursuing narrow self-interest, produces an outcome inferior to what cooperation might have achieved.

Nobody of good faith defends the wall as an ideal. The trouble is that critics of borders too often assume every border is a wall, and proceed to demand its demolition.

The membrane is harder to see

A cell membrane is not a wall. It does not exist to keep everything out. It exists to regulate what passes through — and it does so by osmosis, the quiet, purposeful movement of substance from where it is abundant to where it is needed, governed by the membrane’s own selectivity. Without a membrane, a cell is just chemical soup. The membrane is what allows the interior to maintain the specific concentrations, the particular order, that distinguish a living organism from its surroundings.

Cooperative borders work the same way. They are semi-permeable by design. The Schengen Area did not abolish borders; it replaced non-cooperative ones with cooperative ones, harmonising rules so that crossing served a shared purpose rather than a rivalrous one. A trade agreement does not eliminate the border between two economies; it restructures the border so that passage through it is governed by mutual concession rather than unilateral force. Even the humble customs union is a membrane: it lets goods flow under agreed conditions while maintaining the regulatory distinctiveness that allows each member to function.

The philosopher Michael Walzer made a version of this argument decades ago. Communities, he observed, require boundaries to have meaning. A community that cannot distinguish members from strangers is not a community at all — it is merely a crowd. This is not an argument for cruelty at the border. It is an argument for taking seriously the question of what kind of border we want.

The osmotic pressure on Israel

No country illustrates the membrane problem more acutely than Israel. Its borders are not academic abstractions. They are daily, existential realities — and they encompass both poles of the spectrum.

The peace treaties with Egypt and Jordan represent the cooperative ideal: former adversaries converting walls into membranes, allowing diplomats, tourists, and commerce to pass through under agreed terms. The Abraham Accords extended this logic further, building new membranes where none had existed, linking Israel to Gulf economies across gradients of technology, capital, and energy. That is osmosis at the geopolitical scale — value flowing from where it is concentrated to where it is needed, regulated by agreements that serve both sides.

But Israel also knows what happens when a membrane catastrophically fails. The events of 7 October 2023 were, in the terrible clarity of hindsight, a breach — not of a wall, but of a border that had been functioning as a selective membrane, permitting some eighteen thousand Gazan workers to cross daily for employment in Israeli communities. The permeability that enabled economic cooperation became the vulnerability that enabled massacre. The immediate, instinctive response was to seal the breach: to replace the failed membrane with a wall.

That instinct is understandable. It may even have been, in the short term, necessary. But it is not a permanent answer, because walls do not manage osmotic pressure — they merely dam it. And pressure that is dammed does not disappear. It builds.

Reverse osmosis, or the illusion of forcing the flow

There is a third possibility, and it is the one most frequently attempted by great powers: reverse osmosis. In nature, reverse osmosis forces water against its concentration gradient — from scarcity toward abundance — by applying enormous external pressure. It works, but only for as long as the energy holds. The moment the pump stops, the system reverts.

There is a geopolitical analogy here that should give pause. The American projects in Iraq and Afghanistan were exercises in reverse osmosis: attempts to force liberal democratic norms against the prevailing cultural and institutional gradient through the sustained application of military and financial pressure. For a time, flow was achieved. The moment the pressure was withdrawn, the system reverted — in Kabul’s case, within days. The imposed order had no osmotic logic of its own. It existed only as a function of external force.

Israel, of all nations, should recognise this pattern with particular clarity — not least because it is, literally, a world leader in reverse osmosis. Israeli desalination technology turns the Mediterranean into drinking water by forcing saltwater through membranes under immense pressure. It is an engineering triumph. But the engineers will tell you: reverse osmosis is energy intensive, the membranes degrade, and the process never stops demanding input. It is a solution for water, where no alternative exists. It is a warning for politics, where alternatives must.

The question, then, is not whether borders can be forced into shapes that suit external powers. They can — temporarily, expensively, and with mounting fragility. The question is whether borders can be designed to work with the gradients they actually face.

The paradox of abolition

Here is the deeper problem with the borderless ideal. Remove all membranes and you do not get freedom. You get a new set of walls — cruder, uglier, and less accountable than the ones you dismantled.

This is something close to Le Chatelier’s principle, borrowed from thermodynamics: when you disturb a system in equilibrium, the system shifts to counteract the disturbance. Push toward borderlessness and the system pushes back. The European migration crises illustrate the point. As the EU’s cooperative border arrangements came under strain, what emerged was not a Europe without borders but a Europe of improvised walls — razor wire in Hungary, pushbacks in the Aegean, ad hoc deals with Libyan militias. The membrane failed, and what replaced it was not openness but a patchwork of non-cooperative barriers, each more brutal and less transparent than the system it supplanted.

The same dynamic plays out in economics. The hyperglobalisation of the 1990s and 2000s promised a borderless market. What it delivered was the relocation of borders from the visible realm of tariffs and quotas to the invisible realm of regulatory arbitrage, tax havens, and labour exploitation. The borders did not disappear. They merely moved somewhere less accountable.

The real question

The useful question is never “borders or no borders?” That is a false binary dressed up as moral clarity. Nor is it “how much pressure can we apply?” — the reverse osmosis temptation that exhausts itself. The useful question is: cooperative or non-cooperative? Osmotic or forced?

Israel’s future — like the future of every state navigating impossible pressures — depends on whether it can rebuild membranes where walls now stand. Not naive membranes. Not the permeable border of 6 October, which mistook quiet for equilibrium. But membranes redesigned for the pressures they must actually withstand — selective, transparent, governed by mutual agreement where agreement is possible, and robust enough to hold where it is not.

This is unglamorous work. It lacks the romance of tearing down a wall or the rhetorical punch of declaring that “no human is illegal.” But osmosis does not care about slogans. It responds to gradients — of wealth, of security, of opportunity. The only question is whether those gradients are managed by cooperative membranes, by walls that will eventually be overwhelmed, or by pumps that will eventually run dry.

The membrane is not the enemy of openness. It is its precondition.