DL's Transatlantic load factors are a matter of public record, they have been trending down the last 2-3 years, even as they have tried to reduce capacity, furthermore their JV TA partners have NOT lowered capacity at all, and their load factors have decreased. Beckles, I do not understand your examples? BMI?? BMI maybe had 2 Transatlantic flights tops perhaps 12 years ago, for less than 2 years. AZ is still flying and has actually more TA seats than it did 5 years ago, however the FCO and MXP mix has changed??!!
You want a decade of DL,NW,VS,AF and KL, then vs. now?
Well in a solid decade, I would say that Delta (with NW) has about 10% more flights/seats etc than it did a decade ago. VS has a bit less, then again some of that was rationalization with DL. AF and KL are about 15% up in capacity TA.
Regarding Delta capacity, yes you are right, they now own 49% of VS, so that does add a lot of seats compared to what they had before, as far as I know that while VS has some rationalization and streamlining their capacity, they are pretty flat the last two years.
As for my perception about the competition, considering that the US big three have been raising hell about the ME3 the last 2-3 years and they have done everything they can to keep Norwegian out of the US (and failed), I really do not think its just my perception and anecdotal evidence that is in play here, you are welcome to go read the voluminous documentation commissioned by the big three regarding these subjects.