Even today, more than half a century after the creation of the first atomic bomb, there exists more than enough nuclear weapons to completely eradicate mankind from the face of the earth.
In addition to the U.S., Russia, the U.K., France, and China, there are many other countries which are suspected of possessing nuclear weapons.
The destructive force and accuracy of modern nuclear weapons far exceeds that of those dropped on Hiroshima and Nagasaki. Humanity still lives in fear of them, and their earliest possible abolition is our greatest challenge.