US president pushed world to secure radioactive materials, but the threat of nuclear warfare — and terrorism — remains.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/nuclear-summit-test-obamas-legacy
[2] http://admin.indiaenvironmentportal.org.in/category/author/jeff-tollefson
[3] http://admin.indiaenvironmentportal.org.in/category/journal/nature
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/nuclear-proliferation
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/united-states-america-us
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/nuclear-weapons
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/nuclear-fuel
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uranium