The point was that generally, when Europeans view American patriotism with fear and skepticism, it comes from viewing patriotism in a wider sense through the lens of European historical experience, which includes the relatively recent fascist history of Germany, Italy, Spain, etc.
You equate patriotism with nationalism, and nationalism with violence, as that has been your experience on your continent. My point was not to in any way claim that Europeans are still fascists or that Britain has this problem, I only meant to show that your view of American patriotism may be skewed since you're looking at it through the tinted lens of your history, culture, and experiences which do not exactly correlate with ours.
As for the US' role in preserving world peace, let's pursue a thought experiment: Say the United States dropped off the face of the earth following WW2 and the rest of the world were exactly in tact as it was in 1949. We'll continue to assume that the allies won the war, just for fun.
The Soviet Union would surely have been the world's only superpower for at least 40 years following the war. Logically, Germany would never have been divided in to east and west, and all of Germany would have fallen under the Soviet sphere. NATO would never have existed. The only existing military power in Europe would have been Britain, not strong enough by herself to withstand Soviet influence, and certainly not strong enough to encroach on the USSR's influence of continental Europe.
As such, most of Europe, with Britain as the possible exception, would have been communist, with nations like France, Germany, and Italy being much like today's Eastern European nations.
China would never have opened trade with the West, and it's modern capitalist/communist mix would most likely be purely communist. Japan, a mess after WW2, would never have been rebuilt in to the robust economy it has today. A war between Japan and China would have been likely.
Israel would have fallen to its neighbors, and, in addition to the 6 million Jews that died during the holocaust, several million more would have died in Israel in the years following.
Lacking the grain exported by the USA and lacking any robust economic development in Europe (as a result of Soviet communism), many in third world nations would starve.
Man would never have walked on the moon.
A series of important inventions would never have occurred, or would have occurred later, since they were invented in America.