Trump may be right that most illicit drugs trafficked into the U.S. enter through the U.S.-Mexican border. But history suggests he is wrong that a wall would stop that flow. Decades of failed efforts show that enforcement at the border and interdiction efforts alone have minimal impact on flow of drugs in the country and consumption overall.“The notion that we’re going to fix America’s drug problem by building a wall is just a fantasy,“ said Ethan Nadelmann, executive director of the Drug Policy Alliance, an advocacy organization in support of drug policy reform.
Reliable data on the flow of illicit drugs is scarce, but the data that is available does suggest that a large share of the drugs that enter the U.S. each year do so across the Mexican border. Based on data from U.S. Customs and Border Protection, 97.4 percent of the department’s marijuana seizures during the 2016 fiscal year took place at the southwest border. Around 89.8 percent of cocaine and 87.8 percent of heroin seizures also occurred at the Mexican border. (These figures don’t take into account drugs grown or manufactured in the U.S.)
Most traffickers, however, aren’t climbing over fences at the border or carrying in illegal drugs by foot. The Drug Enforcement Administration says Mexican criminal networks transport the majority of their goods in vehicles or tractor trailers by using legal ports of entry. Drugs are often smuggled in concealed compartments or commingled with other goods.