1951 September 24 - The USSR conducts its second nuclear test. More » 1957 September 19 - First underground nuclear test, code named Rainier, 1.7 kilotons. More » 1961 September 1 - U.S.S.R. resumes nuclear testing after an informal moratorium on nuclear tests between the nuclear powers that began in November 1958. More » 1979 September 22 - South Africa and Israel conduct a joint nuclear test in the South Atlantic. A U.S. Vela satellite detects the explosion. More » 2000 April - The Russian Federation ratifies the Strategic Arms Reduction Treaty (START II). More » 2003 September 25 - The IAEA team in Iran has found additional traces of weapons-grade uranium in Iran. 2007 September 6 - Israel launched an air strike in northeastern Syria. On October 13, American officials confirmed that the site was a partially built nuclear reactor.