When Sanctions Work
I am very skeptical of punitive anti-trade measures such as embargoes and sanctions when it comes to effective foreign policy. Their workability has just not been proven. However, there are a limited number of cases when sanctions may work.
To a lot of people, it makes sense that sanctions would work. Cut a dictator off from his favourite furs and wines, starve his supporters and make them angry, and you either get a dictator who bows to your will, or a furious populace which will install a dictator who changes course in hope of ending the sanctions.
That's the theory, anyway. The reality is somewhat different. It is extremely difficult to name a country where this has actually happened. North Korea, Cuba, Myanmar — these countries have been subject to sanctions for decades without any perceptible effect. Maybe in some indeterminate long run, the repressive regimes in these countries will fall, but as John Maynard Keynes famously pointed out, in the long run, we are all dead — are sanctions really the best course to pursue if millions have to die of starvation and suffer through privation in the meantime?
If anything, there is an equally compelling theoretical framework for arguing that sanctions accomplish precisely the opposite of what they are intended for. After all, the prevailing assumptions are that sanctions are completely effective in cutting dictators off from the resources they need to survive, and that sanctions will generate anger and hate towards their oppressors, rather than the country imposing the sanctions.
There is no real reason to think these assumptions are true; North Korea, Myanmar and Cuba have all found ways to get the weapons and luxuries their ruling regimes require, while by virtue of being cut off from the outside world, their people have an equal reason to believe the propaganda they are fed, and hate the democratic countries refusing to trade with them rather than the regime truly responsible for their suffering. Even if the regime somehow does fall, there is no reason to believe these people would support a government more amenable to democracy or democratic countries.
So if this is the case, when can sanctions work? The answer most likely is, sanctions work when one or both of the conditions mentioned are true. If a regime is unable to obtain the weapons it needs to keep its people in check, or the luxuries its cronies require, it may well fall prey to a well-organised movement against it.
But more importantly, if the people of the country in question are not cut off and separated from the rest of the world, then they will know what they are missing out on. Wealth is really a relative thing, once you have gotten past the basics of survival; the North Koreans and Cubans who are still alive think that they are fine, because they don't know how good they could have it under an alternative system of governmment. Those who know that they don't have to eke out a subsistence living will want something better, and are more likely to blame their oppressors than the countries whose living standards they aspire to.
History does seem to bear this out. One of the few success stories of sanctions is South Africa. The whites of South Africa were not isolated from the rest of the world; they knew precisely what they could not have because of the policies of their government, and they chafed at this. Even then, it was obviously no cakewalk persuading the white South Africans to give up apartheid, but sanctions were probably more effective here than trade.
When it comes to using trade as an instrument of foreign policy, it is crucial to bear in mind that the less the people of the country you are targeting know about the benefits of your system of government, the less likely it is that sanctions will work. In such a case, you want to encourage trade, so as to allow a free exchange of ideas; if your system of government is better, it is bound to prevail and to change minds. If, on the other hand, there has already been a free exchange of ideas, if the people on the other side already know what they are missing out on, then sanctions may very well be a solution.