evidence: It is hard to overstate the impact of America’s fentanyl epidemic. The synthetic opioid and its close chemical relatives were involved in about 70% of the country’s 110,000 overdose deaths in 2022. They are now almost certainly the biggest killer of Americans between the ages of 18 and 49. Every 14 months or so America loses more people to fentanyl than it has lost in all of its wars combined since the second world war, from Korea to Afghanistan.