According to FAS, the U.S. Air Force plans to spend more than $1 billion on developing a guided tailkit for the B61-12 nuclear bomb.
Advocates claimed the increased accuracy will allow the B61-12 to do the job of the 360-kiloton B61-7 bomb while using a 50-kiloton nuclear explosive package from the tactical B61-4 bomb.
[thumb]http://blogs.fas.org/security/2013/04/b61-12tail/[/thumb]