Oil companies ExxonMobil and BP defy the United States by collaborating with Russia in the energy sector. ExxonMobil and BP have separately signed agreements with Rosneft, Russia's state-owned oil company.
Russian President Vladimir Putin warned western leaders Thursday of a potential shutoff of natural gas supplies unless Ukraine pays off the billions it owes for Russian gas. There are alternatives to Russian gas, but the cutoff Putin threatens is a worst-case scenario for Ukraine and broader Europe.
NATO's top military commander says that he will present a package of measures next week laying out how the alliance will respond to the Russian buildup along Ukraine's borders.
Russia's plans to build a natural gas pipeline that bypasses Ukraine to the south is in doubt as the standoff between Russia and Ukraine continues to escalate.