FREE South Africa... Nelson Mandela... ANC ... Desmond Tutu... Soweto... Steve Biko...

The blue poster on a house bulletin board sure was eye-catching--emotionally charged words in large letters and bold fonts scattered across the page. No facts, no argument; just words. The point of the poster? "Vote for Complete Divestment."

Heavy on symbolism and emotion--and devoid of logic--the poster represented what I have come to expect from the divestment movement on campus. Since I came to Harvard three years ago, fully sympathetic to the goal of expunging South-Africa related stocks from Harvard's investment portfolio, I have grown increasingly disillusioned with divestment activists who know exceedingly little and care even less about the probable consequences of further economic sanctions against South Africa.

In general, the idea of economic sanctions is to reduce the welfare of another nation (by disrupting investment, production, trade flows and other economic activity) with the intention of crippling the "target" nation's ability to wage war, convincing it to change specific policies, or even discrediting and toppling the regime itself. In the case of South Africa, either of the last two goals would presumably satisfy divestment activists.

Their plan goes something like this: American companies are pressured into pulling out of South Africa. Widespread economic hardship and dislocation ensue. White South Africans face unemployment, high prices and shortages. Gradually, they come to recognize that the existence of apartheid is the only obstacle to restoring their economic well-being. For the first time since the Second World War, they vote in large numbers against the ruling National Party, and the new government eliminates apartheid and institutes a system of "one person, one vote."

Unfortunately, this scenario--which presumes that Harvard's divestment would represent a genuine sanction, by no means a certain conclusion--ignores or downplays serious threats to "innocent bystanders," namely Blacks in South Africa and neighboring states. Even worse, the chances that economic sanctions will actually produce a peaceful resolution to the tragic situation in South Africa are almost nil.

TO UNDERSTAND why, we need to examine how people react to the imposition of sanctions on their country. Research suggests that when sanctions are applied against democratic states, people become more supportive, not less supportive, of the regime. Enfranchised citizens tend to perceive their government as legitimate, and hence tend to perceive international sanctions as an affront to everyone in the nation, not just the national leaders.

For example, the Arab oil embargo of 1973 was intended to persuade the U.S. and other industrial nations to abandon their support of Israel. Instead of deserting Israel, Americans rallied to its defense, developing an intense anti-Arab sentiment that persists to this day.

When sanctions are imposed against authoritarian regimes, the prospects for success are little better. From Stalin's Russia to Saddam's Iraq, dictators have been able to force their disenfranchised citizens to endure economic hardship in the face of a foreign challenge. Citizens of totalitarian states have no constitutional means for translating their discontent into political change.

The case of South Africa combines aspects of a democratic and an authoritarian state. The vast majority of the population is disenfranchised, but whites enjoy parliamentary government and a modicum of rights. How can we tell how sanctions might work in such a situation?

Fortunately for analytical purposes, there is a historical example nearly identical to South Africa--the case of the white-supremacist government of Rhodesia (now Zimbabwe). In a groundbreaking study of the Rhodesian case, economic historian Johan Galtung concludes that 12 years of total economic embargo--the strongest international sanctions ever imposed before the Iraq-Kuwait crisis--not only failed to break the regime's resolve, but actually solidified it.

The white population of Rhodesia "rallied 'round the flag" against "foreign interference" and learned to evade or endure the hardship brought on by sanctions, much of which they pushed off onto the shoulders of the already-oppressed Black population.

In a response to Galtung's book, historian David Baldwin argued that sanctions had been effective in Rhodesia, because many long-suffering Blacks joined the insurgent National Liberation Front, which eventually toppled the dominant regime by military force. Thus, in the relatively short period of 12 years, sanctions were "successful." In fact, many academic proponents of economic sanctions uphold the case of Rhodesia as their single most successful application.

HEREIN lies the rub for divestment activists. Despite activists' wishful arguments to the contrary, South African Blacks will bear the brunt of economic dislocation brought on by sanctions. Indeed they must; the only way that sanctions can overcome apartheid is if they make Blacks miserable enough to overthrow the government.

Putting pressure on whites will not do any good. Not only are they unlikely to budge in the face of sanctions, they are better able to avoid the pain of sanctions. Many will even benefit by snapping up abandoned foreign concerns at fire-sale prices. The recent weakening of white liberal parties and the growth of ultra-right parties demonstrates the futility of attempting to foment electoral opposition among whites.