Thousands of pounds of fentanyl, a dangerous and addictive opioid, pour into the U.S. every month via the southern border with Mexico. Ingesting as little as 0.25 milligrams of fentanyl can be fatal, which means a single pound has the potential to kill hundreds of thousands of people. Deterring drug trafficking should be a major component of greater border security. Shown below are monthly seizures of fentanyl at the southern border.