I don't think BA is the victim, even if what you say is true. They code share with QF, amongst others, and are a member of Oneworld. The same as AC and Star Alliance and KLM with Skyteam etc.
My point is that each and every airline that becomes a member of an alliance will suffer from a reduced network and frequency, to service the alliance's requirements and the individual airline will tow the line, as that is "what is best for the cooperative".
The enemy may not only be from the east, but within as well.
halas
ps:BA and QF have more to fear, very soon, on the kangaroo route when Jet* get their 787's and start lobbing into Europe where they choose to without any restrictions from an alliance to worry about.
As long as the Canadian government keeps reigns on who is allowed in, then AC may be the Canadian tax payers best investment.