Paul Krugman is out with his latest column sneering at those who worry about inflation. His insouciance about the 1970s reminds us of Mark Twain’s jibe about how Wagner’s music isn’t as bad as it sounds. The Sun, in any event, has shrunk from joining in the warnings about inflation. That’s because of “The New York Sun Reporter’s Handbook and Manual of Style.”

That sacred tome defines inflation as a rise in the price of gold. So far this year, the price of gold has plunged to $1,775 an ounce from $1,943 at the start of the year. That span, though, is just the blink of an eye. It’s the longer view that discloses the catastrophe. The day George W. Bush was sworn in as president, the dollar was at a 265th of an ounce of gold. Since then, the greenback has shed 85% of that value.

This doesn’t worry Mr. Krugman because he doesn’t define inflation the way the Sun does. In a post-column email, about the “tyranny of the 1970s,” the Nobel laureate argues that those inflation-wracked years weren’t so bad: “Real income growth under Jimmy Carter was better than it was under George Bush the elder; the Gerald Ford and Carter era as a whole was better than the reign of George Bush the younger.”

In Mr. Krugman’s world, the scary thing about the 1970s is not so much the inflation as the “other bad news.” He refers to crime, decaying inner cities, and the fact that “we lost the war in Vietnam” (actually, Congress abandoned our allies to the communists, but let’s lay that aside). “The great post World War II boom ended circa 1973, introducing a long period of sluggish gains and often declines in median income,” he notes.

Hmmmm, what was it that happened “circa 1973” to cause the great post-war boom to end and all this mayhem to follow? Could it be that circa 1973 was when America abandoned the Bretton Woods Treaty — meaning, it defaulted on its obligation to redeem in gold at $35 an ounce dollars presented to it by foreign governments? Circa 1973 was when America plunged into the era of fiat money.

Mr. Krugman just doesn’t want to acknowledge that blunder. He loves to talk about the 1950s. “I’m a defender,” he once told Congressman Ron Paul, “of the economic policies that we followed after World War II, that produced the best generation of economic growth that this country has ever experienced. . . . I like the America that my parents prospered in. I think we can restore a lot of that.”

In praising the 1950s, though, Mr. Krugman shrinks from addressing the era’s central feature — a monetary system anchored in gold. Bretton Woods reigned between the end of World War II and the early 1970s. During that period, we had price stability and jobs, with unemployment averaging 4.7%. We understand that the dollar is not a live issue in the 117th Congress. It’s lying in wait, though, for the right Republican.