Like all drug scourges, the fentanyl epidemic that claims so many lives on a daily basis is a matter of supply and demand. The demand, alas, is made in America. The supply, by contrast, is overwhelmingly imported, with a key source being China, where a poorly regulated cottage industry makes the stuff, takes orders over the Internet and ships it via international mail to the United States, Canada and Mexico.

Increased prevention and treatment efforts can curb demand; but it's going to take more enforcement to disrupt the supply chain. That's much easier said than done, and would be even if China's regulatory system were not fragmented and corrupt. Still, authorities on the U.S. side could benefit from a more sophisticated set of tools, which brings us to the good news from Capitol Hill. Yes, good news: Bipartisan legislation that is designed to plug a legal loophole that fentanyl traffickers have exploited for too long is moving toward passage.

A 2002 federal law requires private shippers such as UPS and FedEx to obtain advanced electronic data, or AED, including the names and addresses of senders and recipients on packages, plus details about the parcels' contents. This facilitates screening and identification, ultimately deterring drug suppliers abroad. But the U.S. Postal Service, which receives 340 million packages from abroad annually, is still exempt. The reasons for this had to do with the costs of compliance for the financially troubled Postal Service, and the potential for conflict with other nations' postal systems. As of 2017, the United States had persuaded counterparts abroad to supply AED on more than 40 percent of mail entering the United States, but that mostly reflected enhanced cooperation from Europe and Canada, not China.

Meanwhile, the crisis and loss of life in this country worsened. Wisely, President Donald Trump's commission on the opioid crisis recommended expanded use of AED, and a bill the House just passed would enact that recommendation. The so-called Stop Act, backed by lawmakers from some of the states hardest hit by the fentanyl epidemic, including Sen. Rob Portman, R-Ohio, would require the Postal Service to obtain AED on international mail shipments and transmit it to Customs and Border Patrol on at least 70 percent of international mail arriving to the United States by Dec. 31 and 100 percent by Dec. 31, 2020. Importantly, the Postal Service must refuse shipments for which AED is not furnished. As a sweetener to the Postal Service, in deference to its admitted financial woes, the bill would not require it to pay U.S. customs the same fee as private shipping services until 2020, and then only on a small minority of total imported parcels.

Sens. Orrin Hatch, R-Utah, and Ron Wyden, D-Ore., are prepared to shepherd a bill through the Senate next, so a presidential signing ceremony could take place this summer. Stop Act or no, the nub of the matter is still China's inability or unwillingness to crack down on production of fentanyl and fentanyl precursor chemicals — which would certainly be a better use of its repressive apparatus than, say, jailing dissidents. It sounds like the stuff of a high-level conversation between Trump and his new friend President Xi Jinping.

— Washington Post