The CTBT has long been considered the "Holy Grail" of nuclear arms control and has been advocated by every American president since Eisenhower. The fundamental intent of the CTBT is to cut off the further advancement of nuclear weapons designs by banning their testing. The U.S. Senate shocked the arms control world in October 1999 by rejecting CTBT ratification. Moreover, there are increasing indications that the weapons labs would like to return to full-scale testing (a moratorium has been in effect since 1992), a move that would be sure to inflame international opinion. At the time, the U.S. has demonstrated its capability to develop and produce what are effectively new weapons through the modification of existing weapons (a step which does not require testing), thereby circumventing the intent of the CTBT to begin with.