Despite most other nuclear-capable nations voluntarily honoring a moratorium in the testing of their respective nuclear arsenals for more than 15 years, the Comprehensive Test Ban Treaty has not yet come into force.

The United States’ main concern in ratifying the treaty has been that countries could cheat by claiming small covert weapons tests were actually earthquakes.

But seismic signals from Monday's explosion of North Korea’s relatively small nuclear bomb were clearly identified within minutes as being from a nuclear test, and not from an earthquake, by 39 monitoring stations around the world.

President Obama has said he wants the U.S. Senate to ratify the treaty ahead of a crucial international arms control meeting next year.

While 180 countries have already signed the Comprehensive Test Ban Treaty, the U.S. and eight other nuclear-capable nations whose participation is required have not yet ratified it. Those nations include China, North Korea, India, Pakistan, Indonesia, Iran, Israel and Egypt.

Monday's nuclear bomb test by the Pyongyang government "underlines the urgency of the entry into force of the (treaty) and the necessity of putting an end to all nuclear explosions for all time," said the pact's chief booster, Tibor Toth, who heads the U.N.-affiliated Comprehensive Test Ban Treaty Organization.

Ratification of the treaty would end an era in which eight nations exploded 2,054 bombs in the atmosphere, beneath the sea, in outer space and underground.

Photo: U.S. Military Archive