Economic sanctions can take many forms, but all involve reducing the ability of a country or group of countries to buy the goods they need from other countries. This can be done through the blocking of ports, the imposition of an embargo, or the cutting off of financial aid. These measures can be used to punish a foreign country or to try to force it to change its policies.
The effectiveness of economic sanctions depends on a wide range of factors. A country that imposes sanctions can do so by itself or in cooperation with a number of other nations and intergovernmental organizations. Multilateral cooperation increases the efficacy of sanctions because they limit a targeted country’s options to bypass them. But the choice of which groups to cooperate with — and how quickly — also matters. A more comprehensive set of economic sanctions (embargoes) is less likely to be successful than a smaller set of more limited measures.
In addition to their economic effects, sanctions can lead to suffering among those who are not responsible for a target country’s actions. This is especially true of comprehensive sanctions that seek to cut off all trade, such as the U.S. embargo of Japan during World War II. It is possible for a targeted country to circumvent comprehensive sanctions, as it did by relying on import substitution and smuggling to evade the Great Britain-led Continental blockade of 1807–11 that criminalized all trade with Britain in continental Europe.