Tear gas – the English term – is frequently overheard in everyday conversation in Kampala. Its chemical formula is a semi-permanent climatic feature in the capital. Residents exchange advice on prevailing winds at taxi stages prior to planning their journeys through town. Customers leave online reviews of local businesses that read: “safe place, [no] tear gas or rioting.” Levels of familiarity are such that a local police women’s rugby team in the nearby town of Jinja is named “Jinja Police Teargas Rangers.” And country’s the Finance Minister, Matia Kasaija, recently cited the government’s decision to import rather than manufacture tear gas as a reason for the poor performance of the Ugandan shilling.

Kizza Besigye, Uganda’s opposition leader, is widely thought to be the most tear-gassed man in Kampala. His multiple arrests and detentions have become quotidian event that inspires rolling of the eyes en masse in the capital (he has been under house arrest since last months elections). In 2011, police officers fired a tear gas canister directly into his car during a protest against the rising cost of food and fuel. Apparently disappointed by its effect, they then expended a can of pepper spray in his face, leaving him temporarily blinded.

Tear gas comes in a variety of chemical formulas designed to irritate the mucous membranes, causing coughing, crying, sneezing, breathing difficulties and severe pain in the eyes. Its deployment dates back to the First World War, when xylyl bromide was used to force disoriented soldiers out of their trenches, exposing them to artillery fire.

The proliferation of tear gas around the world owes much to the work of the US General Amos Fries, who spearheaded the creation of an international gas market after the war. Writing in the Atlantic Monthly, Anna Feigenbaum refers to a 1921 article in the trade publication, Gas Age Record, that explains how gas is “admirably suited to the purpose of isolating the individual from the mob spirit,” and is equally effective at dealing with “savages” – a versatility that enamored it to both colonial administrations and law enforcement agencies.

The US remains the largest exporter of tear gas today, due to a sustained alliance between the defense industry, government and the military. Feigenbaum recorded 314 cases of its use around the world in 2013 (not including unreported incidents) – the vast majority of cases being against nonviolent protesters. Uganda came sixth in this global league table and was the most frequent offender in Sub-Saharan Africa.

The Ugandan government began to import tear gas from China in 2011, in line with its shifting economic alliances. A large shipment containing “more than a dozen new tear-gas vehicles” arrived last month, one of which fired at market traders present at a pre-election rally.

Edward (33), who works as a produce vendor in Nakasero market, says he has been exposed to tear gas on five occasions, while David (36), a boda-boda (motorcycle taxi) driver, reports having witnessed 30 separate incidents while driving around the city.

Kampala’s markets have responded to the repeated gassing of the city centre by electing their own defense committees, responsible for keeping lookout, transporting afflicted persons to safe areas and administering towels soaked in water and lemon juice.

Asked about the origins of tear gas in Kampala, Edward doesn’t hesitate: “Museveni is the big man – he is the one that orders it.”

Agnes Nakasujja (49), a spice vendor, interjects: “We feel bad, because we know what is next; we don’t want to have war.” Unlike Edward and David, she remembers the conflicts that afflicted Kampala in the early 1980s, and is unwilling to risk stability by voting for the opposition.

Perhaps the most pernicious effect of the increased deployment of tear gas and military equipment on the streets in Kampala is in the fear that it invokes in the electorate, providing a reminder of the close relationship between the president, the police and the military. As Museveni begins his fifth term as President of Uganda, the growing “mobs” of politically disaffected people in Kampala are likely to be left rubbing their eyes.