To buy cigarettes in Australia, you have to pick up a dull green package plastered with photos of a shriveled infant, a blackened lung or an old man with a tracheotomy hole in his throat. You also need to look closely because the only difference among brands is the name in a small, prescribed font on the bottom quarter of the pack. This arrangement, implemented in 2012, made Australia the first nation both to require graphic images and to ban enticing logos on cigarette packs.

On Thursday, Australian officials announced that the nation's smoking rate fell 15 percent in the past three years — from 15.1 percent of people older than 14 in 2010 to 12.8 percent in 2013.

"This means the daily smoking rate has halved since 1991," said Geoff Neideck, a health spokesman. By comparison, the United States took nearly a half-century to do the same.

Australia's path toward the plain-packaging law wasn't smooth. A long public debate preceded passage of the measure. Philip Morris and other tobacco companies then challenged it in court and before a United Nations tribunal, and they covered some legal fees for several countries to dispute it at the World Trade Organization. The government won the domestic lawsuit, but the other two cases are still pending.

Tobacco researchers say that the drop in the smoking rate shows that plain-packaging laws — as well as the 25 percent tax increase Australia instituted in 2010 — work. These packs help "de-normalize" smoking, disassociating it from hipness and associating it with smoking's health consequences.

Perhaps the fact that cigarette manufacturers are filing lawsuits is evidence enough of the laws' impact — and a sign that the United States should be following in Australia's footsteps.