NORTH KOREA MAY HAVE TESTED A NUCLEAR WEAPON

[Stonecutter]

The united states hasn't tested a nuclear weapon since September 1992. Atmospheric tests are now banned by international law.

Some may remember back in the summer of 1998 India and Pakistan both conducted underground nuclear tests.

edit

read this

http://www.clw.org/control/ctbchron.html

this is useful too

http://nuclearweaponarchive.org/Usa/Tests/