Will targeting nicotine reduce smoking deaths?

The Food and Drug Administration last week announced a proposed rule that would force tobacco companies to dramatically reduce the amount of nicotine in their cigarettes, a step the agency said could save millions of lives by the end of the century.

Nicotine itself is not known to cause cancer, but it is a powerfully addictive substance that is viewed as the main driver of smoking habits that cause roughly 480,000 deaths in the United States each year, the agency said in a statement announcing the potential policy.

Two days later, the...