Just felt the need to add one TINY little thing, reading through some posts here that are complaining (more or less) about the REALISM of this.
Now, this situation is not at all unrealistic. Maybe today, but not in 30-40 years. Definitely not. Relations between major European nations and the U.S. have been on the downfall since the Vietnam war when the 'States refused to withdraw even under pressure of like, 90% of the "civilized world" aka the one that counts in protesting. Including a fair amount of the U.S. itself.
The actual military power of the United States of America is also a delusion. A facade to hide collpasing industries, corrupt economy and national dissent. And the fact that with current rise/fall in industrial output the People's Republic of China will have a greater industrial economy than the U.S. by 2050. Already having greater exports and military industry. May I remind you of WHO won the Vietnam war? The Commies did. What kinda government does Afghanistan, which we've have been fighting so long to make democratic, have now? They're authoritarian. What did we accomplish in Korea? Did we drive the Commies out? Eh? What about Iraq? Have we established freedom liberty and justice to the people of the middle east? And hey, what's up with Israel? They're winning the war too, aren't they? Oh that's right... Israel is just having WAR MOBILIZATION to handel MUSLIM PARTISANS. Or, as we like to call it TERRORISTS. Unorganized groups of Third-world women and children, but the we can't handle 'em, can we?
The United States of America is the greatest country in the world. This is a fact. However, it is a country in Stagnation, and has been so since the middle of the 20th century.
What is, of course, unrealistic is that the European Union would actually be able to gain the influence needed to gather all European nations under one banner and declare all-out war. However, that shall remain the authors mystery.
IF HOWEVER all these countries were united in war, they would beat the living crap out of the U.S.A.
And if China and Russia would join the war? Hell, they'd probably even have more nukes than the 'mericans. (observe that realistic stastistics for this does not exist, of course there is the U.N. statistics, but if you think the 'States doesn't use their influence to exaggerate their own power, you're pretty daft.)
// Politically Concerned, relatively patriotic *cough cough*, Semi-'Merican (I live in Europe, so I guess it can't be more than semi)