evidence: When the history of the fentanyl crisis is written, 2023 may be remembered as the year Americans woke up to an unprecedented threat scouring communities - and a deepening cultural divide over what to do about it. [...] Public health experts say fentanyl, a synthetic opioid far more powerful than heroin, is responsible for the majority of drug deaths. But the supply of illegal drugs is increasingly complex and perilous. [...] "We've had more Americans die of fentanyl than the Iraq, Afghanistan, and Vietnam wars, combined," said Nikki Haley, the former South Carolina governor who is now seeking the GOP presidential nomination, speaking to voters in New Hampshire on Dec. 14.