It was illegal, yet the Europeans still did it.
Err No actually i think you will find that it was the US that started the Bombing.

With economic support from Russia, the Serbs could have rolled over any mainland European country. None have a meaningful standing army with any recent military experience.
Hmmm, Russia were never going support the Serbians in war against any other European country. The Russians really have no interest in going to war with there neighbours who they do most of there business with, And i think you will find that the UK army had plenty of Experience if you care to look it up.

You didn't go to war because without NATO, Russia would have no reason to not cut off your gas supplies
Russia might be supplying more and more Gas to Europe now but i think you will find that at the time of the war in the UK we were still mainly reliant upon our own North Sea oil and Gas supplies. Yes the are now running out but that is well after the conflict.

all the while selling nukes to Serbia
At no point has Russia sold any nuclear weapons to Serbia nor were they ever likely to unless they wanted to start World War 3.

It irks me that liberal Europeans do not realize their very existence and freedoms are only afforded by the actions of a Western superpower willing to fight for the Western world.
It Irks me that so many Americans actually believe that bull.

European history is full of war and bloodshed that culminated in the two biggest, bloodiest wars in human history inside of three decades. After the second time the US decided Europe could not be trusted to behave themselves so we left a few divisions behind in western Europe to ensure they would play nice together while the Soviets did the same to eastern Europe with the added bonus of instituting communist oppression. Western Europe was quite happy to be relieved of the burden of maintaining standing armies, navies, defense perimeters, etc, but was not happy about the ensuing cold war as peace and stability became the two most important things in the European mind. The cold war standoff was the single biggest threat to peace in Europe. Western Europe could not control what the Soviets did, so they tried their best to influence America...
God that's as strange a bastardisation of European History as i have heard.

I suspect the 1 singular difference between Europe and the US is the US has never been involved in a Conflict in the own country. Have your country blown to sh*t a few times an then see if that does not concentrate the minds of people not to want it to happen again.

I think you would see a distinct change in attitude of peoples support for War if you had experienced a couple on your own doorstep.

Fast-forward to 2004. Europe saw the US invasion of Iraq and Afghanistan as yet another threat to their own peace and stability. They desperately want a say in US policy to prevent such threats and they get rather agitated when we don't listen. They don't realize (or want to acknowledge) the fact that they have been lecturing us for 200+ years on how we're "doing it all wrong" and like you would do with a nagging wife who won't shut up we Americans have learned to simply tune out whenever the lectures begin yet again.
No you don't get it at all do you, you really don't understand Europeans if you think that, and to talk of us as 1 entity is just strange Europe consists of nearly 50 countries do you really think that they are all the same ??