Seems to me the pressing interest of the us and European governments is keeping Putin's power and influence in the region in check. He's very clearly shown his willingness to use whatever means he likes including military force and assassination to expand his power in the region. Everyone remembers the impacts of the USSR doing the same. A success here could embolden him further so its in their interest to push back.

No doubt economic concerns are part of the equation but IMO its a bit tinfoil hattish to suggest its purely about some particular shale gas deal.