President Trump has signed a bill imposing sanctions on Russia a week after the measure was passed by the Senate with a veto-proof majority. (Michael Klimentyev/Sputnik/European Pressphoto Agency)

Sanctions are again the talk of Washington. At the time of writing, the United States is considering or is in the process of extending economic sanctions on several countries, including some major geopolitical foes: Russia, North Korea, Iran and Venezuela.

The use of sanctions in such contexts is far from unusual. You could probably argue that sanctions are among the most popular tools for responding to major foreign crises. The problem, however, is that nobody is quite sure whether they actually work.

This is not a new quandary. WorldViews considered it before, in April 2014, when the Obama administration announced sanctions on Russians close to Vladimir Putin in response to Moscow's aggression in Ukraine. Below is a long excerpt from that post, which pointed to an academic study of sanctions and their usefulness:

One of the best-known investigations of that question is “Economic Sanctions Reconsidered,” first published in 1985, by Gary Clyde Hufbauer, Jeffrey J. Schott, Kimberly Ann Elliott. That book, now on its third edition (from 2009), attempts to access the aims and success of every economic sanction for which it can find data.

According to the latest edition, the sanctions listed below are the only instances from 1914 to 2008 in which not only was the stated goal of the measures reached, but the sanctions themselves were instrumental in achieving that goal — thus receiving a full rating of 16 out of 16.

It isn't a long list, and many of the entries are a little obscure. Where possible, the cost to the nation targeted has been included:

1921: the League of Nations vs. Yugoslavia

In 1921, the League of Nations threatened economic sanctions against Yugoslavia if it attempted to seize land from Albania. Yugoslavia backed down.

1925: the League of Nations vs. Greece

Four years later, the League of Nations threatened sanctions against Greece unless it withdrew from Bulgaria's border territory. Greece withdrew.

1948-1949: the United States vs. Netherlands

As the Dutch East Indies struggled to become an independent Indonesia after World War II, the United States suspended the Marshall Plan aid to authorities in the region after the Dutch arrested Indonesian leaders. After threats of sanctions, the Dutch agreed to Indonesian independence in 1949. The sanctions cost 1.1% of the Dutch gross national product.

1958-1959: the U.S.S.R. vs. Finland

During the “Night Frost Crisis” of 1958 and 1959, Finnish-Soviet relations were fraught after the Communists were excluded from government and Karl-August Fagerholm, viewed as unfavorable to the Soviets, was appointed as prime minister. The U.S.S.R. used economic sanctions to force Fagerholm's resignation. The sanctions cost 1.1.% of the Finnish GNP.

1961-1965: the United States vs. Ceylon (Sri Lanka)

Between 1961 and 1965, the United States applied sanctions against the Dominion of Ceylon (what is now Sri Lanka) after the socialist government of Sirimavo Bandaranaike was accused of expropriating the assets of U.S. and British oil companies. The government fell in 1965, largely because of the economic effects of these sanctions, which cost 0.6% of the country's GNP.

1965-1967: the United States vs. India

In 1965, the United States canceled food and military aid to India in a bid to force it to change its agricultural policies and to voice displeasure over its war with Pakistan earlier that year. In 1966, Indira Gandhi's government proposed new agricultural policies, and U.S. aid resumed the next year. The economic cost was 0.08% of the Indian GNP.

1975-1976: the United States vs. South Korea

In 1975, the United States used the threat of sanctions to discourage South Korea from buying a nuclear fuel reprocessing plant from France, which the United States thought might be secretly used to help make nuclear bombs. South Korea never bought the plant.

1976-1977: the United States vs. Taiwan

In 1976, the United States learned that Taiwan was secretly developing nuclear weapons, so the United States delayed its export of nuclear material to the country. Taiwan later announced that it was abandoning its plans. The estimated economic cost was 0.1% of Taiwan's GNP.

1982-1986: South Africa vs. Lesotho

South Africa applied economic pressure on Lesotho to make it return South African refugees with links to the African National Congress. After a military coup in Lesotho, South Africa lifted a blockade on the landlocked nation, and 60 ANC members were deported back home. The cost was estimated to be 5.1% of Lesotho's GNP.

1987-1988: the United States vs. El Salvador

In 1988, the United States used economic sanctions to block El Salvador from releasing those accused of killing U.S. citizens.

1992-1993: the United States vs. Malawi

The United States (and other nations) significantly cut aid in 1992 in a bid to improve the democratic standards and human rights situation in Malawi. Malawi was largely reliant on aid (the sanctions were estimated to cost 6.6% of its GNP) and swiftly adopted more open policies. After a referendum, multiparty democracy was introduced in 1993, and aid was soon resumed.

1993: the United States vs. Guatemala

In 1993, after President Jorge Serrano dissolved Congress and said he would rule by decree, the United States and European nations threatened sanctions. Business owners, scared of the economic effects, helped force Serrano out of power and installed a new president, Ramiro de León Carpio. The economic cost was said to be 1.3% of Guatemala's GDP.

1994-1995: Greece vs. Albania

Greece suspended European Union aid to Albania in 1994 after five members of an ethnic Greek group in the country were given prison terms. After this economic pressure (said to have cost Albania 2.9% of its GNP), Albania reduced the sentences and released two, and Greece resumed aid.

As we noted at the time, given that the study looked at 200 sets of sanctions, this wasn't a reassuring argument for their effectiveness (and, more damningly, some experts have argued that the definition of sanctions used in the study is too broad).

On a more positive side, it should be noted that the list ends in 2008 and, as such, mostly avoids the targeted sanctions on individuals, companies or institutions that became more widely used afterward (such as in 2014 in Russia).

However, the fact that sanctions are being expanded in 2017 doesn't speak well to previous sanctions' effectiveness, and some of the situations being responded to are so complex that it is hard to gauge how economic measures will influence them.

Can sanctions really force a belligerent and ideological North Korea to forsake its weapons program, for example, especially if major powers like China and Russia won't fully cooperate and the country has already been under significant sanctions for more than a decade? And Venezuela is deep into an economic nightmare — how will targeted sanctions on its dwindling elite be effective?

The case of Iran is especially confounding. Many would argue that sanctions finally brought Tehran to the negotiating table, resulting in the 2015 nuclear deal with the United States and other world powers. But President Trump and many other Americans don't believe that was a good deal and want to back out of it. Meanwhile, many Iranians believe that U.S. sanctions in response to their country's ballistic missile program are a violation of the agreement.

And then there's Russia. Obama-era sanctions on the country seem to have had an effect on its economy. However, they also gave Moscow an excuse for its own financial mismanagement in the face of falling oil prices. The situation in Ukraine is far from resolved, and Russia is now in Syria, helping to prop up the regime of Bashar al-Assad.

And, of course, everyone knows by now that Russia stands accused of meddling in the 2016 U.S. election — despite the targeted sanctions that were already in place.

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