This post is part of the Tracking the Effects: Environmental History and the Current United States Federal Administration series edited by Jessica DeWitt, Shannon Stunden Bower, and Niiyokamigaabaw Deondre Smiles. Submissions for this series are being accepted on an ongoing basis. Learn more here.
During Donald Trump’s presidential campaign in December 2023, he stated that unauthorized immigrants (often called migrants in contemporary discourse) were “poisoning the blood of our country.”1 Since entering office, Trump has accelerated deportations, with a goal of deporting one million immigrants per year. The Trump administration has shut down projects former President Biden started, which had given as many as four million unauthorized immigrants the ability to remain lawfully within the US.2 The Trump administration has lifted the ban on authorities accessing various databases to identify unauthorized immigrants and given Immigration and Customs Enforcement (ICE) the right to enter schools, churches, and hospitals for arrests.3 These changes have created an atmosphere of fear not only for unauthorized immigrants, but also for legal residents, especially those who are non-white.
One of the strategies to keep immigrants from coming into the USA is 42 U.S. Code § 265, often called Title 42. It states that people coming from countries with communicable diseases that are a threat to American safety can be prohibited from entering the country.4 The law was used as reason for keeping immigrants out of the USA during the COVID-19 pandemic. Trump has discussed using it again to control immigration, ostensibly targeting control of diseases such as severe flu strains, tuberculosis, and scabies.5
This is not the first time that immigration has been connected to disease as an excuse for racism. Looking back to the American responses to World War II, we can see similar intersections of disease and immigration in attitudes and actions toward Japanese.
This is not the first time that immigration has been connected to disease as an excuse for racism. Looking back to the American responses to World War II, we can see similar intersections of disease and immigration in attitudes and actions toward Japanese.
Constructing the Japanese as threat via the mosquito
The Japanese first arrived on the American colony of Hawai’i in the 1800s as a part of the workforce in the Hawai’ian sugar industry.6 By the time of the Pearl Harbor attack on 7 December 1941, there were 130,000 Japanese Americans living in the US and an additional 150,000 in Hawai’ian territory.7 They had made a clear imprint on the West Coast, and approximately two-thirds of them were born in the US, making them official US citizens.8 Despite this, longstanding racist attitudes from white Americans led to hostility toward those with Japanese ancestry.9 Citizens of Japanese descent were put on the Custodial Detention list in 1938 to identify them as persons who could potentially betray America.10
Immediately after the attack on Pearl Harbor, President Roosevelt ordered the internment of 8,000 Japanese, 2,300 Germans and a few hundred Italians.11 Then “Executive Order 9066” in February 1942 delegated power to the Secretary of War to “prescribe military areas … from which any or all persons may be excluded.”12 Over 100,000 civilian Japanese Americans, including men, women, and children, were designated an “enemy race” and placed in ten American internment camps.13
During the hostilities in the Pacific, the Office of War Information (established 1942) used various forms of propaganda to increase support for the Allies. Enemies of the US, including the Japanese, were often portrayed in a cartoonish way, drawing on racist tropes.14 One of the goals of American propaganda was to identify the Japanese as something that soldiers should find easy to kill. The Japanese were generalized as a “mass of vermin” instead of individuals.15 American propagandists used vermin metaphors for Japanese more often than for Germans.16
The Office of War Information thought that mosquitoes were an apt comparison to the Japanese. War creates the perfect homes for mosquitoes: trenches and craters fill with water, creating breeding grounds. Anopheles mosquitoes, which often take advantage of these conditions, carry malaria. Malaria is caused by the parasite Plasmodium, and it causes life-threatening fever, among other symptoms.17 Malaria’s battlefield significance was seen several times during WWI, when entire battles were cancelled because the troops on both sides were stricken.18
During WWII, US military leadership was highly concerned about limiting mosquito-borne disease transmission. The Malaria Control in War Areas (MCWA) division was established in 1942 to promote heathy policies. Still, disease was rampant. In the Pacific theater, physician Paul Russell recalled that two-thirds of the troops were sick with or recovering from malaria, leaving only a third of the troops fit to fight.19 Authorities determined that some people were not taking the risks seriously: troops were not taking the prescribed antimalarial drug Atabrine and antimalaria squads, which were specially trained teams to remove mosquitoes and mosquito-breeding habitat, were not in place.20 To combat this lax behavior, troops were reminded constantly about the dangers of mosquitoes through cartoons and radio broadcasts.21
In WWII propaganda posters, the fight against mosquitoes was often compared to the fight against human enemies. Some of these posters (Figure 1 and 2) made direct comparisons between the Japanese and mosquitoes by describing them both as enemies and illustrating them with the same yellow color. This was a reference to the “yellow peril,” a phrase used to refer to the threat of the Japanese by building on racial tropes of Asian skin color. Putting Japanese people and mosquitoes side-by-side established the two as enemies of equal significance and urgency. In other posters, cartoon mosquitos were depicted with features intended to evoke Japanese people and were given wings displaying the “rising sun” motif of the wartime Japanese flag (Figure 3). The text on the poster included in Figure 3 highlights the human-made places where mosquitos breed, encouraging soldiers to avoid making malaria havens. By giving the mosquitoes Japanese features, not just the other way around, mosquitoes were construed as an enemy that should be taken just as seriously as the wartime enemy.
Other posters, such as Figure 4, are more subtle with their comparisons. This poster incentivized soldiers to “fight the peril behind the lines,” the dreaded mosquito, but the use of the word “peril” also created an association to the “yellow peril” of the Japanese. The text of the poster declared that mosquitoes are deadly “between sundown and sunrise,” not only pointing to the mosquitoes’ active hours, but also alluding to the rising sun motif on the Japanese flag.
WWII posters aimed at troops served as double propaganda, showing both enemies at once and reinforcing the severity of both. Caricaturing the Japanese in this manner turned them into something subhuman, which could have made it easier for American soldiers to be more brutal in combat. As environmental historian, Edmund Russell III, discussed in his article “Speaking of Annihilation,” enforcing the idea that enemies are subhuman vermin normalized the prospect of extermination.22 These posters portrayed war as pest control and pest control as war and were intended to bolster American efforts to eliminate both insect and human enemies.23
In wartime, dehumanization was intended as a prelude to extermination. The dehumanizing rhetoric of the current American federal administration points in similarly horrifying directions.
In wartime, dehumanization was intended as a prelude to extermination. The dehumanizing rhetoric of the current American federal administration points in similarly horrifying directions. Immediately after taking over as President on January 20, 2025, Trump made a proclamation to protect the United States “from invasion.” In the proclamation he stated concerns about the “innumerable aliens potentially carrying diseases of public health” crossing the border. Justifying his actions in the guise of public health and safety, he used this proclamation to ramp up deportations. Examining WWII-era American propaganda clarifies the dangers of weaponizing public health to drive dehumanization.
Notes
1 Kate Sullivan, “Trump’s anti-immigrant comments draw rebuke,” CNN, October 6, 2023, https://archive.is/aMefi
2 Muzaffar Chishti & Kathleen Bush-Joseph, “In First 100 Days, Trump 2.0 Has Dramatically Reshaped the U.S. Immigration System, but Is Not Meeting Mass Deportation Aims,” MPI, April 24, 2025, https://www.migrationpolicy.org/article/trump-2-immigration-first-100-days
3 Ibid.
4 42 U.S. Code § 265 – Suspension of entries and imports from designated places to prevent spread of communicable diseases. https://www.law.cornell.edu/uscode/text/42/265
5 Charlie Savage, Maggie Haberman & Jonathan Swan, “Sweeping Raids, Giant Camps and Mass Deportations: Inside Trump’s 2025 Immigration Plans,” The New York Times, November 11, 2023, https://archive.is/wTOMr#selection-563.0-563.88
6 G. Y. Okihoro, “The Japanese in America,” in Japanese AmericanHistory: An A-Z Reference from 1868 to the Present, ed. B. Niiya (Facts on File, 1993), p.1.
7 R. Daniels, “Incarceration of the Japanese Americans: A Sixty-Year Perspective” The History Teacher 35, no. 3 (2002), p.299.
8 R. Laher & A. G. Neal, “The Internment of Japanese Americans during World War II: a Case Study of National Trauma and Institutional Violence,” Scientia Militaria South AfricanJournal of Military Studies 34, no. 1 (2006), p.8
9 Ibid.
10 T. Kashima, “Custodial detention / A-B-C list,” Densho Encyclopedia, December 18, 2023, https://encyclopedia.densho.org/Custodial%20detention%20/%20A-B-C%20list
11 Ibid.
12 Daniels, “Incarceration of the Japanese Americans,” p.302.
13 Ibid.
14 T. Witkowski, “World War II Poster Campaigns–Preaching Frugality to American Consumers,” Journal of Advertising, 32, no. 1 (2003), p.72. https://www.researchgate.net/publication/235360889_World_War_II_Poster_Campaigns– Preaching_Frugality_to_American_Consumers
15 E. P. Russell III, War and Nature (Cambridge University Press, 2001), p.98.
16 E. P. Russell III, “’Speaking of Annihilation’: Mobilizing for War against Human and Insect Enemies, 1914-1945,” The Journal of American History, 86 no.4 (1996), p.1522.
17 “Malaria,” World Health Organization, 11 December 2024, https://www.who.int/news-room/fact-sheets/detail/malaria.
18 A. Spielman & M. d’Antonio, Mosquito (Faber and Faber, 2002), p.142
19 Ibid.
20 Ibid.
21 Spielman & d’Antonio, Mosquito, p.143.
22 Russell, “Speaking of Annihilation”, p.1522.
23 Russell, War and Nature, p.99.
Marion Jørgensen
Great read! Well researched with captivating images! If you continue in this line of research, there’s a lot on the boll weevil, Mexican guest workers, and the Bracero program during WWII and after.