Here is a link to a free version of the cited paper mentioned by Rezwan -
When a practical and inexpensive source of fusion neutrons from D-D or D-T fusion becomes available,
our lives will change.
Abundant natural supplies of fertile materials (U-238 and Th-232) can be bred into excellent fissile material (Pu-239 and U-233) with fusion neutrons.
The neutronicity of D-D and D-T fusion reactors exceed by approximately an order of magnitude fission breeder reactors.
A 1Gw Molten Salt Breeder reactor (ORNL-3996) optimized to breed U-233 without protactinium removal can produce about 37 kilograms of U-233 per year .
A PACER D-D fusion reactor scaled to 1GWe is expected to breed 8125 kilograms of U-233 per year .
To produce a 10 kt tactical nuclear weapon would require about 20 kilograms of military grade fissile material
This is a 220 times advantage to the fusion system for producing fissile with a fission suppressed Thorium Blanket installed within the fusion target chamber (or cavity).
If you do not have physical custody of the fusion reactor capable of producing a high fluence of inexpensive fusion neutrons, then it is not possible to insure that a fission suppressed breeding blanket is not retrofitted to the fusion reactor to make weapons useable fissile materials. Producing really high quality military grade materials capable of producing high yield explosions is more challenging and requires more infrastructure (Purex or Thorex reprocessing, etc).
 - ORNL-3996 - http://www.energyfromthorium.com/pdf/ORNL-3996.pdf
 - HACER: A Grand Design for Fusion Power by Walter Seifritz - http://home.comcast.net/~aeropharoh/SeifritzHACER1.pdf
Minority view - Thus far, nuclear weapons have actually saved lives and reduced major direct conflicts between major world powers over the last 60 years.
Ending WWII via use of two nuclear weapons averted a terrible, bloody, and scaring, direct assault of the Japan home islands. Without use of nuclear weapons, military planners
anticipated ~1 million US soldiers and sailors and perhaps 2 million Japanese soldiers and civilians dying in the operation to take the Japanese home islands.
The use of nuclear weapons was actually merciful (although I would have wished that the record could have read that the first nuclear weapon was used to make a demonstration test before the Japanese militarists on an uninhabited island before it was used against the Japanese people).