There's such a thing as being too grateful, as
is said in The Human Factor, by Graham Greene, if I got the message correctly. However, that seems to be what
this person is asking from us europeans, in the article Europeans are worse than cockroaches, by Mark Steyn: we must be forever grateful for guarding us against russians, Hitler, the Kaiser, and the martians.
He makes several mistakes, but the first one is to consider Europe as something homogeneous: every country has its own story, and not every country has to be grateful, or maybe they have to be grateful for several reasons. But, in any case, gratefulness shouldn't be taken too far, and asking to do so is asking too much.