New weapons technologies continue to develop.
Robotic soldiers right out of 'The Terminator' are not far away:
http://www.defensetech.org/archives/001377.html
http://www.defensetech.org/archives/001246.html
Chemical explosives continue to become
more powerful, so that the gap between 'conventional' and 'nuclear' weapons may be blurred one day:
http://www.technologyreview.com/arti...012105.asp?p=1
And even basic 'guns' are developing into new forms that use no 'propellant', have no sound, muzzle flash, or recoil, and can fire at unbelievable rates:
http://www.defensereview.com/modules...rticle&sid=526