A draft copy of the new Nuclear Posture Review that leaked out this month has set off a flurry of hand-wringing in Washington, especially since the draft says the administration is interested in enhancing its arsenal with smaller “low-yield” nuclear weapons.

The posture review will be released at the end of this week. In the meantime, policy experts are debating whether the changes mean the future of civilization is at greater risk, or whether the world is made safer if the U.S. nuclear umbrella has a broadened range of capabilities, not just multi-megaton weapons that could destroy life on the planet as we know it.