US Secretary of State John Kerry has said he hopes the current situation in Crimea will not have an impact on cooperation with Russia over the ongoing destruction of Syria's chemical weapons.
Mr Kerry also said the US is "convinced" that the Syria could move faster on the destruction programme than it is currently.
An unusually frank Nato Secretary General issued an unequivocal warning on the course of events should Russia attack Latvia or Estonia.
The West responds with sanctions and closer political ties with Ukraine as Russia's President seals the annexing of Crimea to much fanfare.
Supporters of the controversial fracking industry believe shale gas could be America's most potent weapon in the stand-off with Russia.