--- title: Slippery slope url: https://propagandaarchive.org/techniques/slippery-slope/ description: 'Slippery slope: arguing a small step leads to disaster with no evidence. Examples: Eisenhower''s domino theory, Park Chung Hee, Santorum, Dobbs.' section: Techniques --- ![Illustration: a dossier collage of an intelligence briefing room with case files and behavioral-analysis notes on a chalkboard.](https://propagandaarchive.org/static/generated/hero-learn.jpg) Techniques · Rhetorical # Slippery slope 1. [Home](https://propagandaarchive.org/) 2. [Techniques](https://propagandaarchive.org/techniques/) 3. Slippery slope In brief Slippery slope is an argument that one step will set off a chain of further steps ending in disaster, with no evidence for the links; examples include Eisenhower's 1954 domino theory, Park Chung Hee's 'lose the whole of Southeast Asia', the 1941 Dutch SS poster, Santorum's 2003 remarks and the 2022 Dobbs debate. A chain backed by evidence is a causal argument, not the fallacy. On this page - [History and effect of Slippery slope propaganda](https://propagandaarchive.org/techniques/slippery-slope/#history-and-effect-of-slippery-slope-propaganda) - [How Slippery slope propaganda works](https://propagandaarchive.org/techniques/slippery-slope/#how-slippery-slope-propaganda-works) - [Why Slippery slope propaganda works](https://propagandaarchive.org/techniques/slippery-slope/#why-slippery-slope-propaganda-works) - [Slippery slope propaganda examples across eras and sides](https://propagandaarchive.org/techniques/slippery-slope/#slippery-slope-propaganda-examples-across-eras-and-sides) - [How to spot Slippery slope propaganda](https://propagandaarchive.org/techniques/slippery-slope/#how-to-spot-slippery-slope-propaganda) - [Where Slippery slope propaganda ends: edge cases and legitimate persuasion](https://propagandaarchive.org/techniques/slippery-slope/#where-slippery-slope-propaganda-ends-edge-cases-and-legitimate-persuasion) - [The science](https://propagandaarchive.org/techniques/slippery-slope/#the-science) Related techniques [Fear appeal](https://propagandaarchive.org/techniques/fear-appeal/) [False dilemma](https://propagandaarchive.org/techniques/false-dilemma/) [Straw man](https://propagandaarchive.org/techniques/straw-man/) [Card stacking](https://propagandaarchive.org/techniques/card-stacking/) [Red herring](https://propagandaarchive.org/techniques/red-herring/) Also called Slippery slope fallacy, Domino theory, Thin end of the wedge, Camel's nose, Floodgates argument Claim that one modest step will set off a chain of further steps ending in catastrophe, without showing that each link in the chain is likely. ## How to spot Slippery slope: the tell A short sentence leaps from a small first step to an extreme last one ("if we allow X, soon Y, and then Z"), with the middle links asserted rather than evidenced and no stopping point considered. ## What Slippery slope is not A causal chain whose links are each supported by evidence, such as a documented precedent-extension effect or a dose-response relationship. On this page ## History and effect of Slippery slope propaganda The argument form is old and the label is newer. Logic textbooks treat it as a fallacy when the chain is assumed instead of shown; legal scholars treat it as a real phenomenon when the mechanism can be named. Eugene Volokh's article "The Mechanisms of the Slippery Slope" (*Harvard Law Review*, vol. 116, 2003) defines the basic form as the claim that adopting decision A will make a later decision B more likely, and then sorts the cases by the mechanism that would carry it, such as changed attitudes or lowered costs. That split between a named mechanism and an unnamed one is the practical test used on this page. Explain moreShow less In propaganda the form works because it moves the audience's attention from a present, modest and often reasonable step to a distant and frightening end state. The listener is asked to judge the end state, not the step. The emotional effect is dread of loss of control: once the first domino falls, nothing can be done. That makes the argument hard to answer in the moment, since the speaker's prediction concerns the future and cannot be checked yet, and the cost of ignoring it is made to sound unlimited. Every political side has used the form. This page documents it in a US Cold War doctrine, a South Vietnamese leaflet, a Nazi-occupation recruiting poster, a Soviet-bloc doctrine, and recent US debates in which both the right and the left have argued from slopes. The question asked of each is the same: were the links shown, or only asserted? Lineage: Informal logic (slippery slope fallacy, thin end of the wedge, domino argument) ## How Slippery slope propaganda works 1. **Pick a small first step.** Usually one the audience may find reasonable on its own: a treaty, a ruling, a boycott, a tolerance of one case. 2. **Chain it to a larger step.** "Then" and "next" carry the argument. Each link is stated as certain, though each is only probable at best. 3. **End on a catastrophe.** The last link is the feared outcome: conquest, tyranny, moral collapse, the loss of "everything". Show all 5Show fewer 1. **Remove the brakes.** The chain assumes nothing intervenes: no court, no vote, no second thought, no cost to the next actor. 2. **Make the first step the only place to stop.** The speaker's remedy is to refuse step one, which turns a policy choice into a barricade. Explain moreShow less The form travels with [Fear appeal](https://propagandaarchive.org/techniques/fear-appeal/), since the end state has to frighten, and with [False dilemma](https://propagandaarchive.org/techniques/false-dilemma/), since "stop now or lose everything" leaves out the middle. It also leans on [Card stacking](https://propagandaarchive.org/techniques/card-stacking/), because the facts that would break the chain (other states' own resistance, other courts, earlier steps that did not slide) are usually not mentioned. ## Why Slippery slope propaganda works Vivid, feared outcomes feel more probable than they are, and people judge likelihood by how easily an example comes to mind ([Availability heuristic](https://propagandaarchive.org/learn/availability-heuristic/)). Threats and losses weigh more than the same-sized gains ([Negativity bias](https://propagandaarchive.org/learn/negativity-bias/)), and fear messages persuade more when they come with a clear action to avoid the threat ([Fear messaging](https://propagandaarchive.org/learn/fear-messaging/)). The affect attached to the final image (a tank, a flag, a funeral) colours the judgement of the first step before the middle links are examined ([Affect heuristic](https://propagandaarchive.org/learn/affect-heuristic/)). ![Illustration: an empty speaker's podium with a cluster of vintage microphones and rows of empty chairs.](https://propagandaarchive.org/static/generated/graphics/empty-podium.jpg) Illustration, not an archive object ## Slippery slope propaganda examples across eras and sides - **United States, 1954.** At a news conference on 7 April 1954, during the siege of Dien Bien Phu, a reporter asked President Dwight Eisenhower about the strategic importance of Indochina. He answered with what became known as the domino theory: "Finally, you have broader considerations that might follow what you would call the 'falling domino' principle. You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly. So you could have a beginning of a disintegration that would have the most profound influences." The chain (Indochina, then its neighbours, then further) was a real policy claim by a head of government, made to build support for aid to the French. The point for this page is the form: the rate and certainty of the later falls were asserted by analogy. - **United States, 1964, an internal check.** On 9 June 1964 the CIA's Board of National Estimates, signed by its chairman Sherman Kent, answered a presidential question on whether the loss of South Vietnam and Laos would set off a "domino effect" in the Far East. The memorandum, published in *Foreign Relations of the United States* (1964-68, vol. I, document 209), concluded that "with the possible exception of Cambodia, it is likely that no nation in the area would quickly succumb to communism" and that any spread would take time and was not inevitable. Historians read the memo differently: some call it a challenge to the theory, others a qualification of it. The record is that the US government's own analysts doubted the speed and certainty of the chain while the public form of the argument stayed in use. - **South Korea and the US-South Vietnamese programme, 1965 to 1969.** An English-language sheet in the allied psychological warfare series, numbered 2 under the heading "SOUTH KOREA", opens with a quotation attributed to President Park Chung Hee: "If we fail to block the communist invasion in South Vietnam we will lose the whole of Southeast Asia, and the Republic of Korea's own security cannot be guaranteed." The sheet adds photographs of Korean units in action and states the "aggression" framing as fact. The chain runs from South Vietnam to the whole region to Korea's own security. The sheet is undated and prints no issuer; NARA places it in a 1965 to 1969 range. See [South Korea: The Common Struggle, Korean Army, Navy and Marine Units Help in the Common Fight Against Aggression](https://propagandaarchive.org/collection/south-korea-common-fight-against-aggression-1965-1969/). Show all 9Show fewer - **South Vietnam, 1966.** A narrow two-panel cartoon leaflet, titled in Vietnamese "Today / Tomorrow: why the Viet Cong carry out the policy of 'forced conscription'", shows armed men seizing a young man at left and bodies lying across a field under smoke and aircraft at right. Taking a recruit today is shown ending in mass death tomorrow, with nothing between the two panels. The leaflet carries no printed issuer; Wikimedia Commons applies a South Vietnamese government tag. See [Hôm nay / Ngày mai: tại sao Việt Cộng thi hành chánh sách 'cưỡng bách tòng quân' (Today / Tomorrow: why the Viet Cong carry out the policy of 'forced conscription')](https://propagandaarchive.org/collection/hom-nay-ngay-mai-forced-conscription-cartoon-1966/). The sheet describes one side's recruitment only and gives no evidence for the step from a single seizure to a field of dead. - **Nazi-occupied Netherlands, July 1941.** A lettering-only poster (white on red), catalogued by the Stadsarchief Deventer as July 1941 and issued for the recruiting of the Freiwilligenverband Niederlande (a Dutch branch of the SS-Freiwilligen-Standarte Nordwest), is headed "Bolshevism throws off the mask". It asks: "Must religion and culture be destroyed here too?" and continues: "All Europe is marching against the danger. Dutchmen, your existence is at stake. Do not wait until it is too late." The German attack on the Soviet Union had begun on 22 June 1941. The chain is from events in the east to destruction in the Netherlands, with enrolment as the only stop. The poster says nothing of the German occupation of the Netherlands that already existed. See [Het Bolsjewisme gooit het masker af (Bolshevism throws off the mask)](https://propagandaarchive.org/collection/het-bolsjewisme-gooit-het-masker-af-1941/). - **Soviet Union and the Warsaw Pact, 1968.** In *Pravda* on 26 September 1968 S. Kovalev's article "Sovereignty and the International Obligations of Socialist Countries" argued that the sovereignty of a socialist state could not be set against the interests of world socialism, and that the weakening of any link in the socialist system "directly affects all the socialist countries". Brezhnev's speech to the Fifth Congress of the Polish United Workers' Party in Warsaw (12 to 13 November 1968, depending on the source) restated it as policy; the argument had been used to justify the invasion of Czechoslovakia in August 1968. It is called the Brezhnev Doctrine in the West. The structure is the domino argument turned inward: a reform in one member would bring down the rest, so intervention in that member is a duty. Scale differs from the 1954 American case in one plain respect. Eisenhower's argument was made to a free press and a Congress about aid; the Soviet one was made after, and in defence of, an armed invasion of an allied state. The Soviet government under Mikhail Gorbachev later repudiated the doctrine. - **United States, 2003, the right.** In an April 2003 interview with the Associated Press, Senator Rick Santorum, discussing the pending *Lawrence v. Texas* ruling on sodomy laws, said: "If the Supreme Court says that you have the right to consensual sex within your home, then you have the right to bigamy, you have the right to polygamy, you have the right to incest, you have the right to adultery." In the same interview, speaking about the definition of marriage, he said it was not "man on child, man on dog, or whatever the case may be"; Santorum later said he had not meant to equate these acts with homosexuality. The chain runs from the Court's reasoning on private adult conduct to a list of unrelated acts. Senators Susan Collins and Lincoln Chafee, both Republicans, publicly criticised his remarks. The wording here is from press reports of the interview. - **United States, 2022, the left and the right.** The majority opinion in *Dobbs v. Jackson Women's Health Organization* (24 June 2022), written by Justice Samuel Alito, said that nothing in it should be understood to cast doubt on precedents that do not concern abortion. In a separate concurrence Justice Clarence Thomas wrote: "In future cases, we should reconsider all of this Court's substantive due process precedents, including Griswold, Lawrence, and Obergefell." Commentators and officials on the left argued from this that contraception and same-sex marriage rights were next, and Congress passed the Respect for Marriage Act later in 2022. Commentators and officials on the right answered that no such cases were before the Court and that the worry was unfounded. Both positions use the slope form: one says the first step opens the way to the rest, the other says the proposed safeguard answers a chain that does not exist. The factual record is that one justice, in a one-justice concurrence, named three precedents, and that the majority disclaimed the reach. Which reading is a fallacy or a forecast is left to the evidence of what the Court later takes up. - **Netherlands, 1983, a causal claim on the other side of the left-right line.** Anti-apartheid protesters outside the Tweede Kamer in The Hague held a banner reading "No boycott = more violence in South Africa!" above a stained party flag (Anefo, Nationaal Archief, 21 June 1983). The equals sign puts a policy choice and a future harm in one equation. It is a causal claim with some chain behind it (the claim being that sanctions would hasten political change and so reduce violence), and the page records the sign, not its truth. See ["Geen boykot = meer geweld in Zuid-Afrika" banner and stained CDA flag, The Hague (1983)](https://propagandaarchive.org/collection/geen-boykot-meer-geweld-bloody-cda-flag-1983/). ![A US-South Vietnamese allied psychological warfare sheet quoting President Park Chung Hee on losing Southeast Asia](https://propagandaarchive.org/collection/images/south-korea-common-fight-against-aggression-1965-1969.jpg) ![Two-panel Vietnamese leaflet labelled Today and Tomorrow, showing a conscription scene and a field of bodies](https://propagandaarchive.org/collection/images/hom-nay-ngay-mai-forced-conscription-cartoon-1966.jpg) ![Red lettering-only Dutch poster, Het Bolsjewisme gooit het masker af, recruiting for the Freiwilligenverband Niederlande](https://propagandaarchive.org/collection/images/het-bolsjewisme-gooit-het-masker-af-1941.jpg) ![Protesters outside the Dutch parliament holding a banner Geen boykot = meer geweld in Zuid-Afrika above a stained flag](https://propagandaarchive.org/collection/images/geen-boykot-meer-geweld-bloody-cda-flag-1983.jpg) Explain moreShow less *"South Korea: The Common Struggle", English-language photo sheet in the U.S.-South Vietnamese allied psychological warfare programme, 1965 to 1969 (undated; issuer not printed). National Archives and Records Administration, 306-VP-011-19 (NAID 26326282). Unrestricted.* *"Hôm nay / Ngày mai" (Today / Tomorrow), Republic of Vietnam government leaflet, 1966. Marine Corps Archives & Special Collections (Gary Carlson Collection), via Wikimedia Commons. Public domain (PD-South VietnamGov). Graphic content: shown as it was distributed.* *"Het Bolsjewisme gooit het masker af", recruiting poster, Den Haag, July 1941 (Stadsarchief Deventer), via Wikimedia Commons. Public domain (PD-anon-70-EU).* *Protest outside the Tweede Kamer, The Hague, 21 June 1983, photograph by Rob Bogaerts for Anefo, Nationaal Archief 932-6281. CC0 1.0.* ## How to spot Slippery slope propaganda - **Count the links.** Write the chain out step by step. If the speaker names only the first and the last, the middle is a claim without support. - **Ask what stops each link.** Courts, voters, costs, other states' own interests and plain delay all slow real chains. An argument that assumes none of them is a slope. - **Ask for the rate.** "Very quickly" and "certainly" carry the argument. How fast, by what mechanism, with what earlier cases? Show all 6Show fewer - **Look for earlier steps that did not slide.** If similar first steps were taken before and the chain did not follow, the speaker should say why this time differs. - **Check the remedy.** A slope usually ends in "so do nothing", or "so do exactly what I propose". Ask whether a limit at step one would also solve the worry. - **Apply it to your own side.** Slopes feel obvious when a rival makes them, and less so when your own camp does. ## Where Slippery slope propaganda ends: edge cases and legitimate persuasion A chain of consequences is not a fallacy when each link has evidence. ![Illustration: a vintage broadcast microphone beside torn script pages.](https://propagandaarchive.org/static/generated/graphics/spot-microphone.jpg) Illustration, not an archive object A chain of consequences is not a fallacy when each link has evidence. Law is full of real slopes: a court that extends a principle in one case often finds the same principle invoked in a nearby case, and Volokh's 2003 article sets out several mechanisms, including attitude changes and lowered costs of the next step, that carry that process. Medicine, finance and engineering routinely argue from small deviations to larger failures (a tolerance that creeps, a debt that compounds), and those arguments are tested with data. In foreign policy, the July 1914 crisis is the textbook case of a regional dispute carried into a continental war by alliance obligations. Friedrich Hayek's *The Road to Serfdom* (1944) argued that central economic planning tends toward political coercion; economists and historians continue to dispute the claim, which shows it is a testable empirical argument and not a bare fallacy. The test is whether the chain was shown. The domino theory is the instructive case because the evidence came in afterward. After 1975, South Vietnam, Laos and Cambodia came under communist governments, but Thailand, Malaysia, Indonesia, the Philippines and Singapore did not. Critics read this as evidence against the theory. Defenders, including Singapore's Lee Kuan Yew, who in October 1967 told US officials that the region should use the time the US war effort had bought (FRUS 1964-68, vol. XXVI, docs 284-287), argued that the American stand gave those states time to consolidate, a claim historians still contest. Either way, the 1954 form of the argument offered the later falls as near-certain, and the 1964 CIA memorandum shows that US analysts at the time considered them neither quick nor inevitable. A good faith slope argument names the mechanism, gives the rate and the stopping points, admits where it fails, and can be tested. The reverse also holds: dismissing a real chain as "just a slippery slope" is a mistake of its own. The label does not settle the question. The page records the argument's form; whether a given slope was real is for the evidence. ### Sources - Dwight D. Eisenhower, press conference, 7 April 1954 (the "falling domino" passage; transcript reproduced at [australianpolitics.com](https://australianpolitics.com/1954/04/07/eisenhower-domino-theory-press-conference.html/)). - Board of National Estimates (Sherman Kent) to the Director of Central Intelligence (McCone), 9 June 1964, *Foreign Relations of the United States, 1964-1968*, vol. I, document 209: [history.state.gov/historicaldocuments/frus1964-68v01/d209](https://history.state.gov/historicaldocuments/frus1964-68v01/d209). - "South Korea: The Common Struggle", National Archives, 306-VP-011-19 (NAID 26326282): [catalog.archives.gov/id/26326282](https://catalog.archives.gov/id/26326282). - "Hôm nay / Ngày mai", Marine Corps Archives, via Wikimedia Commons: [commons.wikimedia.org](https://commons.wikimedia.org/wiki/File:Propaganda_Leaflet,_1966_(17137019975).jpg). - "Het Bolsjewisme gooit het masker af", Stadsarchief Deventer, via Wikimedia Commons: [commons.wikimedia.org](https://commons.wikimedia.org/wiki/File:Het_bolsjewisme_gooit_het_masker_af.jpg). - S. Kovalev, "Suverenitet i internatsional'nye obyazannosti sotsialisticheskikh stran", *Pravda*, 26 September 1968, p. 4; Brezhnev's Warsaw speech of 12 to 13 November 1968 (sources differ; dates and summary from secondary reference works, see [Brezhnev Doctrine](https://en.wikipedia.org/wiki/Brezhnev_Doctrine) and its bibliography). - Associated Press interview with Rick Santorum, April 2003, as reported in [CNN, 23 July 2015](https://www.cnn.com/2015/07/23/politics/rick-santorum-homosexuality-comments-same-sex-marriage/index.html) and [ABC News, 2012](https://abcnews.com/blogs/politics/2012/01/rick-santorum-in-the-hot-seat-again-for-gay-marriage-stance). - *Dobbs v. Jackson Women's Health Organization*, 597 U.S. ___ (2022), opinion of the Court and Thomas, J., concurring: [law.cornell.edu/supremecourt/text/19-1392](https://www.law.cornell.edu/supremecourt/text/19-1392). - Eugene Volokh, "The Mechanisms of the Slippery Slope", *Harvard Law Review* 116 (2003): [law.ucla.edu/volokh/slippery.pdf](https://www2.law.ucla.edu/volokh/slippery.pdf). - Protest outside the Tweede Kamer, 21 June 1983, Anefo, Nationaal Archief 932-6281, via Wikimedia Commons. *Sourcing note (11 October 2026): the Eisenhower, FRUS and Thomas passages were read directly or confirmed against transcripts. The Kovalev and Brezhnev dates and the Santorum wording come from secondary reports and should be checked against the primary text. The date of signature of the Respect for Marriage Act was not confirmed and is not stated. Lee Kuan Yew's 1967 position is from secondary summaries.* Sources and further reading ## The science Research on the psychology this technique relies on, from the Learn library: Research on the psychology this technique relies on, from the [Learn](https://propagandaarchive.org/learn/) library: - [Availability heuristic](https://propagandaarchive.org/learn/availability-heuristic/) — Availability heuristic - [Negativity bias](https://propagandaarchive.org/learn/negativity-bias/) — Negativity bias - [Fear messaging](https://propagandaarchive.org/learn/fear-messaging/) — Fear messaging - [Affect heuristic](https://propagandaarchive.org/learn/affect-heuristic/) — Affect heuristic ## Slippery slope propaganda examples in the collection [Slippery slope in the collection](https://propagandaarchive.org/collection/technique/slippery-slope/) - [Het Bolsjewisme gooit het masker af (Bolshevism throws off the mask)](https://propagandaarchive.org/collection/het-bolsjewisme-gooit-het-masker-af-1941/) (Nazi Germany · Jul 1941 · Fear appeal, Bandwagon, Slippery slope). Content note: Waffen-SS volunteer recruiting poster using anti-Bolshevik fear language - [South Korea: The Common Struggle, Korean Army, Navy and Marine Units Help in the Common Fight Against Aggression](https://propagandaarchive.org/collection/south-korea-common-fight-against-aggression-1965-1969/) (United States · 1965 · Testimonial, Card stacking, Slippery slope) - [Hôm nay / Ngày mai: tại sao Việt Cộng thi hành chánh sách 'cưỡng bách tòng quân' (Today / Tomorrow: why the Viet Cong carry out the policy of 'forced conscription')](https://propagandaarchive.org/collection/hom-nay-ngay-mai-forced-conscription-cartoon-1966/) (South Vietnam · 1966 · Fear appeal, Slippery slope). Content note: Cartoon panel showing a field of dead soldiers under aircraft and smoke, and a young man being seized by armed men. ## Propaganda techniques related to Slippery slope [Fear appeal](https://propagandaarchive.org/techniques/fear-appeal/) [False dilemma](https://propagandaarchive.org/techniques/false-dilemma/) [Straw man](https://propagandaarchive.org/techniques/straw-man/) [Card stacking](https://propagandaarchive.org/techniques/card-stacking/) [Red herring](https://propagandaarchive.org/techniques/red-herring/)