Violent clashes in Colombia between the military and protesters, many angry over tax increases on the poor, since early May reflect a continued breakdown of Colombian society. A 2016 peace process brought an end to armed conflict after more than 50 years. But over the past two years, leftist forces — including the Revolutionary Armed Forces of Colombia, or FARC, and the National Liberation Army, or ELN — have reemerged to demand political power and control. Conservative opponents, their right-wing paramilitary organizations and government forces have responded forcefully. The drug cartels, many aligned with both sides, continue their reign of terror. In between, many Colombians again find themselves trapped in a cycle of violence.

But the United States has also played a substantial role in this conflict, by providing the military equipment now being used by security forces to forcibly quell dissent. Starting under the Lend-Lease Act during World War II, U.S. military strategy focused on providing aid to anti-communist regimes throughout the world. During the 1990s, that policy combined with efforts to stop the flow of cocaine and heroin into the United States, ultimately militarizing security forces in Latin American countries. The consequences of this strategy are now fully on display in the streets of Colombia — and being borne by Colombians.

Starting before World War II, the United States developed a strategy of arming allies and becoming what President Franklin D. Roosevelt called the “arsenal of democracy.” This continued in the Cold War as the fight against communism led to continued military support for allies, including totalitarian ones.

The trend escalated in the late 1990s with the implementation of Plan Colombia. President Andrés Pastrana proposed a “Marshall Plan” for Colombia in 1999 to stop the production of coca and opium by uplifting peasants reliant on the crops. The Clinton administration approved the concept, hoping to balance security and counternarcotics operations with social and economic development. The continued civil war and burgeoning drug trade pushed the United States to heighten its interest in the country, despite the absence of Cold War imperatives.

However, from the beginning the majority of aid went to the security forces — over 75 percent of the nearly $2 billion in the first year. Soon, American military advisers poured into the country, including 500 in the year 2000, following a pattern over many years of relying on military solutions rather than the infinitely more complex economic and social ones.