"ANCHORAGE -- President Barack Obama on Tuesday will propose a faster timetable for buying a new heavy icebreaker for the U.S. Arctic, where quickly melting sea ice has spurred more maritime traffic, and the United States has fallen far behind Russian resources."

"With warming seas creating new opportunities at the top of the world, nations are scrambling over the Arctic — its territorial waters, transit routes and especially its natural resources — in a rivalry some already call a new Cold War."

"The United States is investigating whether the Islamic State used chemical weapons, the White House said Thursday, following allegations that IS militants deployed chemical weapons against Kurdish forces in northern Iraq."

"The U.S. Coast Guard has been forced to divert resources - including a vessel that fights cocaine trafficking - to the Arctic this summer to ensure that Royal Dutch Shell's exploratory oil drilling meets its environmental and safety commitments, its top officer said."

"For the first time, the U.S. Department of Defense has detailed what it views as its greatest challenges related to climate change. In a report to Congress, the Defense Department said that global warming poses a 'present security threat, not strictly a long-term risk.'"

"Federal regulators have begun a push for new cybersecurity defenses to prevent sophisticated attackers from penetrating utility control rooms and other industrial control system centers by infiltrating malware on third-party vendors' products."

"VIENNA — Iran and a group of six nations led by the United States have agreed to a historic accord to significantly limit Tehran’s nuclear ability for more than a decade in return for lifting international oil and financial sanctions against Iran, a senior Western diplomat involved in the negotiations said on Tuesday."

"The Army set out to develop lead-free bullets to protect the environment. The finished product achieved that goal -- and produced the most lethal rifle round to date."

"Hackers have made the energy industry a favorite target."

"The toxic vapors acted quickly against the Second Platoon of the 811th Ordnance Company, whose soldiers were moving abandoned barrels out of an Iraqi Republican Guard warehouse in 2003. The building, one soldier said, was littered with dead birds."