Nicholas Spiro, managing director at Spiro Sovereign Strategy, says the crisis in Ukraine has escalated "dramatically" as "Cold War rhetoric" is being used.
As tensions continue to rise between Ukraine and Russia, here is a look at the people at the center of the conflict.
President Obama wants to nudge the EU toward fresh sanctions against Russia over Ukraine.
Annika Falkengren, CEO of SEB Bank, comments on the bank's activity in Ukraine, Russia and the Baltic countries, and says activity in Sweden and Germany is picking up.
Christian Esters, senior director for sovereign ratings at Standard and Poor's Ratings Services, says the reasons behind Russia's credit rating downgrade include capital outflows and increased risks of slower growth.
Scott Key, CEO of IHS, says investment confidence in Russia will end as companies look to less risky markets.
Andrew Wood, former British ambassador to Moscow, says the rule of Russian president Vladimir Putin is more "fragile" than the Communist party's during the Iron Curtain days.
Kerry's statement came as tensions escalated in Ukraine and the recent agreement in Geneva teetered on the verge of falling apart.
Disruption from the Russia-Ukraine conflict is not the only threat to Europe's energy supplies—there's also Algeria.
There's something that everyone's missing about gold and the situation in Ukraine.
Ukrainian forces killed pro-Moscow rebels as they closed in on the separatists' military stronghold in the east and Russia launched army drills near the border in response.
The big environmental argument for nuclear energy: Its carbon emissions are the lowest among major power sources.
Eduard Zehetner, CEO of Immofinanz, explains that he wrote off exposure to Ukraine property five years ago, but that investments in Moscow property are the most profitable he has in his portfolio.
Russia's defense minister announces new military exercises, reports CNBC's Michelle Caruso-Cabrera on events taking place in Eastern Ukraine.
Warning Russia that new sanctions are "teed up," President Obama accused Moscow of failing to live up to an agreement to ease tensions in Ukraine.
U.S. President Barack Obama said he was poised to impose new sanctions on Moscow if it does not act fast to end an armed stand-off in Ukraine.
It is time for the US to change Putin's calculations, and Syria is the place to do it, says New America Foundation's Anne-Marie Slaughter.
Samir Brikho, CEO of AMEC, says the geopolitical tension in Europe from the Ukraine crisis is "alarming" for energy security.
Uros Cufer, finance minister of Slovenia, says tough sanctions are "hurting" the European economy and a "softer touch" should be adopted by the European Union.
Alastair Newton, senior political analyst at Nomura, says markets are underestimating the risk of Russian military action in eastern Ukraine.