The Pentagon had something juicy to say.

The other day, according to them — the people in the Pentagon, and the people who speak for them — were out in the Nevada desert, with a couple of B-2 bombers from the United States Air Force. Strapped to their underbellies were two atomic bombs. Nukes. Fat men. Little boys. Seven-hundred-pounds of fission that could blow up a metropolis with just one detonation.

Only, they weren’t really real. They were but fakes, designed to ready our military, through practice, but not actually devastate (or in this case “ruin”) a landscape. Even if it’s a barren wasteland in the American West.

Id est, there were no warheads in the things.

One was what’s called an “earth penetrator” for underground use, and the other was a “tactical version of the B61”, according to Defense One.

More from them:

“The primary objective of flight testing is to obtain reliability, accuracy, and performance data under operationally representative conditions,” said the statement from the National Nuclear Security Administration, the Energy Department arm that oversees such tests. “Such testing is part of the qualification process of current alterations and life extension programs for weapon systems.”

But why now? Perhaps it has to do with tensions with Russia, which are higher than they have been in decades, and which have sparked fears of a new nuclear arms race. Earlier this week, the Russian government announced it would conduct a massive drillto prepare its citizens for nuclear war.

But it may also have to do with the Pentagon’s quest to replace its decades-old nuclear arsenal with new bombs and delivery vehicles, an endeavor whose price tag tops several hundred billion dollars. The Air Force, for one, has been making its casefor new intercontinental ballistic missiles and a nuclear cruise missile. At an Air Force Association conference in the Washington suburbs last, Boeing touted its work on the Minuteman III ICBM, mounting large-scale models of the long-range missiles front and center in its sprawling display area.

Did you know that there is a new version of this B61 (which has been around since the days of JFK and Sandy Koufax) scheduled to be ready sometime in the early 2020s?

The bill for that? For new bombs, bombers, subs and the rest? Upwards of half a trillion bucks.