How Sanctions Actually Move Money

Sanctions are usually reported as a gesture: a country "targets" an oligarch, a ministry "hits" a bank, a president signs an order in front of the flags. What the headline hides is the machinery. Modern financial sanctions do not seize anything at gunpoint. They work by quietly denying access to the pipes through which money moves, and they are effective in proportion to how central those pipes are. To understand why a paragraph in a Treasury press release can freeze a firm in Dubai or Shenzhen within days, you have to look at the plumbing rather than the politics. Four pieces do most of the work.

1. The list

It starts with a name on a list. In the United States the list is the SDN list (Specially Designated Nationals), maintained by a small office inside the Treasury called OFAC, the Office of Foreign Assets Control. Being added does two things on paper: it freezes any assets the party holds inside US jurisdiction, and it bars US persons from doing business with them. Read narrowly, that sounds like a domestic measure, the sort of thing that should trouble you only if your money sits in New York. Its global reach comes from the second piece, and it is the piece almost everyone underestimates.

2. The dollar chokepoint

Roughly half of world trade is invoiced in dollars, and almost every cross-border dollar payment, wherever it begins and ends, passes through a bank in the United States. A bank in Nairobi that wants to pay a supplier in Bangkok in dollars does not fly banknotes across the ocean. It routes the payment through an account it holds at a US bank, a "correspondent account", and that New York leg is where the dollar actually clears. That leg is the chokepoint. The moment one of the parties appears on the SDN list, the US bank is forbidden to process the transfer, and the foreign bank that tried it risks losing its own correspondent account, which is to say its access to dollars at all.

So banks in every country screen every payment against a list published in Washington. Not because Washington issues them orders, but because the alternative is exile from the world's reserve currency. This is also the mechanism behind the phrase "secondary sanctions": a firm with no American operations that keeps dealing with a designated counterparty can itself be designated, and cut off in turn. It is coercion exercised through the ledger, reaching entities that no US law could directly command. Power without a single soldier crossing a border.

"Sanctions work through the dollar, not the border. The list is written in Washington; the enforcement happens in every compliance department on earth."

3. SWIFT, the address book

Here is where the popular story goes wrong. Cutting a country off "from SWIFT" is routinely called the nuclear option, as if SWIFT were the money itself. It is not. SWIFT is a cooperative based in Belgium that carries standardized messages between more than 11,500 institutions in over 200 countries, on the order of 53 million messages a day in 2024. It moves the instructions, not the funds. Disconnecting a bank from SWIFT is closer to deleting it from the phone book than to emptying its vault: the money can still move, but arranging the move becomes slow, manual, and expensive, and every counterparty starts to wonder whether it is worth the trouble.

Because SWIFT sits under EU law, the bloc has been able to turn it into a weapon twice. Iranian banks were disconnected in 2012, reconnected in 2016 after the nuclear deal, and partly cut again in 2018. Designated Russian banks were removed in 2022. Genuinely disruptive, but the point is that this is the second-order lever. A bank barred from SWIFT can still pick up a telephone. A bank barred from dollar clearing has lost the currency.

4. Freezing versus seizing

The most ambitious use of the plumbing is the immobilisation of a central bank. When Russia invaded Ukraine in February 2022, roughly 300 billion dollars of Russian central bank reserves were frozen across the West. Note the verb: they were frozen, not confiscated. A large share, on the order of 180 to 190 billion euros, happens to sit at Euroclear, the Belgian securities depository, for the mundane reason that this is simply where the bonds were parked.

Freezing is easy. You instruct the custodian not to let the owner touch the account. Seizing is another matter entirely. Handing the principal to Ukraine would mean taking another sovereign state's property, which tests centuries of legal doctrine on sovereign immunity and risks unsettling every other reserve manager who keeps money in the West. So the West has taken a revealing middle path: it spends the interest instead. Those immobilised bonds keep earning, Euroclear booked billions in such windfall profits (close to 6.9 billion euros in 2024 alone), and in June 2024 the G7 agreed to lend Ukraine about 50 billion dollars, serviced by that stream of earnings. The principal stays frozen. The yield goes to the war. It is the neatest possible summary of how far the tool can currently stretch, and where it stops.

Why the plumbing leaks

The system's greatest strength doubles as its advertisement. Every time reserves are frozen, every unaligned central bank in the world learns the same lesson: dollar reserves are usable only with Washington's continued permission. The response is entirely rational. Build other pipes. Russia extended its own messaging system and wired it to Iran's; a growing slice of trade is settled in local currencies, in barter, and in gold, an asset no one can switch off remotely (the subject of a companion piece). None of this yet threatens the dollar's dominance, because nothing else on earth can absorb reserves at that depth. But a chokepoint is a tool that dulls with use. The harder you squeeze it, the stronger the incentive for everyone else to dig a channel that runs around it.

For an investor the practical reading is that "dollar dominance" is not only an economic fact but a political asset, and political assets carry a maintenance cost. Sanctions are the clearest proof that the financial system is not neutral infrastructure but a lattice of chokepoints, and that whoever owns the busiest one owns a lever. The open question is the one every empire built on plumbing eventually meets. How many times can you turn off a customer's water before they decide to dig their own well?