"North Korea defiantly celebrated its fifth nuclear test Friday, claiming that it can now make warheads small enough to fit onto a missile and warning its "enemies" — specifically the United States — that it has the ability to counter any attack."

"Syrian government forces have been accused of dropping barrel bombs containing chlorine from helicopters on a suburb of Aleppo, injuring 80 people."

"Libya has shipped the last of its chemical weapons stocks out of the country on a Danish vessel, under a UN-backed plan to eliminate the arsenal, officials said Tuesday."

"The clandestine group’s goal was clear: Obtain the building blocks of a radioactive 'dirty bomb' — capable of poisoning a major city for a year or more — by openly purchasing the raw ingredients from authorized sellers inside the United States."

"Rising sea levels due to hurricanes and tidal flooding intensified by climate change will put military bases along the U.S. East Coast and Gulf Coast at risk, according to a report released on Wednesday."

"Multi-ethnic nations are vulnerable to armed conflicts after weather disasters such as heatwaves and droughts in a trend that could worsen with global warming, scientists said on Monday."

"A Utah militia group leader accused of trying to blow up a federally owned cabin in Arizona talked about his plans to go on the offensive and strike back by damaging government buildings and vehicles in a secretly recorded video played in court Thursday."

"The aftermath of the cyberattack in Ukraine on Dec. 23, 2015, produced two unexpected lessons that U.S. grid operators have started to take to heart."

"A month after hackers blacked out power in western Ukraine, a team of U.S. security experts touched down in Kiev to piece together the extraordinary assault."

"As Ukraine's civil war raged, a few mouse clicks at three local power companies set in motion the covert intrusion. It was the first successful attempt at planting a bug, then disabling an electric grid serving hundreds of thousands of people."