Chinese chemical companies are playing a major role in the U.S. fentanyl crisis as the main producers of ingredients needed to make the drug.

Strained relations between Beijing and Washington are undermining efforts to stop the flow of those chemical building blocks, and thus impeding the struggle against illicit fentanyl. …

A few years ago, a joint effort to limit the flow of illicit fentanyl was a successful point of collaboration in a tense U.S.-China relationship. In 2018, China restricted the production and sale of two of the most common ingredients for the drug, a move that won it praise from the U.S.

Since then, the U.S. has adopted a tougher posture toward China, while China has also grown more assertive about defending its interests. As a consequence, the cooperation on combating the drug trade has broken down.

[Or perhaps one reason for the breakdown in the relationship is that China wasn’t performing to its agreements on the illicit drug trade, which has grown steadily worse even during the period of this supposed cooperation. — Ed]