-Daniel aka Obsidian
But as Keck notes, that difference in explosive power doesn't tell the entire story. "What makes the B61-12 bomb the most dangerous nuclear weapon in America’s arsenal is its usability," Keck writes. "This usability derives from a combination of its accuracy and low-yield." According to the Federation of American Scientists, the B61-12 will be able to strike within 30 meters of its target. This accuracy allows the bomb to destroy targets that would have previously necessitated the use of a larger but more indiscriminate weapon.
As a result of the bomb's relatively low yield, the weapon would produce less nuclear fallout than earlier nuclear weapons, something which would limit unintended casualties from a nuclear attack. But this lower fallout also lowers the cost and scope of a nuclear strike — which could in turn increase the possibility that the bomb would actually be used in a military engagement.
As it is, the B61-12 may actually expand the range of possible US nuclear targets. In a 2014 conference organized by the Stimson Center, retired US Air Force General Norton Schwartz said that the B61-12's target set goes beyond that of previous gravity-guided nuclear bombs in the US military. This effectively means that the US could now consider the use of aircraft-delivered lower-yield nuclear weapons in a wider range of scenarios.
The concern over the B61-12 — and the thing that could make it is the most dangerous bomb in the US arsenal — is that such an accurate and usable nuclear weapon could encourage military thinkers to start imagining a wider variety of situations in which the use of nuclear weapons would be acceptable.
Once the B61-12 is fully tested and deployed, it will be integrated into existing NATO forces and the F-35 in order to enhance the alliance's nuclear posture in Europe.