Have to quote myself, edited to slow....
"They could nuke a split in the continental crust between Europe and Russia and then blockade the waterway. So we don't get oil, gas, ore, wood, food, tanks and other weapons and everything we could ever need from Russia and China. After that they do the same to SaudiArabia and tow it with superhuman NAVY SEALS through the Pacific and dock it on the east coast."
We could blockade the ports of Denmark, the UK, the Meditteranean, and of course the Bospurus. We could easily keep the ME and Saudi Arabia away from you under our thumb. Russia may assist you though I doubt it they would be more likely to just sit back and watch maybe grab some more territory near the end. The blockade won't be total but it could severly restrict your economy giving us a strategic advantage.
@Ziggys Russia yes but I'm not sure they'd help you... Norway also yes but if we blockade the Baltic how are you going to transport it? Remember oil pipelines are the first thing we'ed bomb.
Russia wouldn't have to assist us, we're only talking business here. They take our money now, they would take our money then. Infact, they will become part of the "europeon freetrade zone", though i don't know if there is an exact timeline until when the process shall finish.