What is a sanction, and do sanctions actually work?

A sanction is a restriction one government, or a group of them, imposes on another state, organisation or individual in order to change their behaviour. It occupies the space between a formal protest, which carries no cost, and military force, which carries a great many. That middle position explains both why sanctions are used so readily and why the arguments about them are so unresolved.

Who can impose them

The distinction that matters most is between sanctions imposed by the United Nations Security Council and everything else. When the Security Council adopts a sanctions resolution under Chapter VII of the UN Charter, every member state is legally obliged to implement it. These are the only sanctions that are genuinely global, and they are correspondingly hard to obtain, because any of the five permanent members can veto them.

Everything else is unilateral or regional. When a single country imposes sanctions, or a bloc such as the European Union does so, the measures bind only those within that jurisdiction. Their practical weight therefore depends less on legal authority than on economic gravity — on how much of the world’s finance, trade or technology runs through the territory doing the imposing.

What form they take

Comprehensive sanctions target an entire economy, restricting broad categories of trade and finance with a country. They are now comparatively rare, largely because of what was learned from their humanitarian consequences: a measure aimed at a government tends in practice to fall on the population it governs, while leaving the leadership’s own position largely intact.

Targeted measures — often called smart sanctions — were the response. Rather than an economy, they name specific people and entities: asset freezes on named officials and companies, travel bans, arms embargoes, and sectoral restrictions that cut off particular industries such as defence, energy or advanced technology while leaving food and medicine trade formally untouched.

Then there are secondary sanctions, which are the reason sanctions reach much further than the jurisdiction imposing them. These penalise third parties — a bank or manufacturer in an uninvolved country — for doing business with a sanctioned entity. A firm with no legal obligation to follow another country’s sanctions may still comply scrupulously, because losing access to a major financial system would cost it more than the sanctioned business is worth.

Do they work?

This is genuinely contested, and anyone claiming a clean answer is overstating the evidence. The difficulty is partly definitional: success depends entirely on what the sanctions were for. Measured against the demand that a government abandon a policy it considers vital to its survival, sanctions have a poor record. Measured against narrower aims — degrading a weapons programme’s supply chain, raising the cost of a course of action, signalling that a norm has been broken, or creating leverage for a later negotiation — the record is considerably better.

Targeted regimes also face a persistent practical problem: money and goods route around them. Front companies, intermediaries in non-participating jurisdictions, relabelled shipments and informal payment networks all erode a sanctions regime over time, and enforcement is a continuing effort rather than a one-off act. Broad participation matters enormously here, which is part of why Security Council measures, when they can be agreed, carry weight that unilateral ones do not.

The costs that are easy to miss

Sanctions are frequently described as a peaceful alternative to war, and relative to war they plainly are. They are not, however, costless to the people living under them. Even carefully targeted regimes produce over-compliance: banks and shippers, facing severe penalties for getting a judgement wrong, tend to withdraw from a sanctioned country altogether rather than assess each transaction. The result can be that humanitarian exemptions written explicitly into the rules turn out to be difficult to use in practice, because no bank will process the payment.

There is a cost to the imposing side as well — lost exports, higher prices, and an incentive for the targeted state to build alternative payment and supply arrangements that reduce the leverage available next time. None of this settles whether a given sanctions regime is justified. It does explain why the decision is a harder one than the language of a peaceful alternative tends to suggest.