BBRus-
What is your basis to make this statement?
If I were to be accepted by British Airways, I can assure the last thing I would think about is to get my flight training and TR sponsored by BA and go back to Spain. Actually, I doubt anyone would give up a career in British Airways to start from scratch in another airline in their country of origin.
You would be signing a contract which will contain a clause of permanence.
I just wanted to add something to this post because I feel it needs saying.
To all you 'starry eyed wannabe's' (which I was one myself barely 7 years ago), especially those who would be considering relocating countries to avail themselves of this opportunity...
BA, or most majors for that matter, isn't/aren't bad places to be at all but I assure you after a little while it will just be a job and home is always home.
I work for a far eastern legacy and there are a lot of relatively senior guys I fly with that are on
a ton of money (considerably more than I make), who will leave at the drop of a hat when airlines start hiring again in their home country. If you're Spanish, for example, for most Spaniards it would take a hell of a rewarding and well renumerated job in the UK to make up for what you would miss as far as weather/food/culture/friends/family for the long term. It doesnt seem it at the time when you're sat in your first jet and get your first few pay cheques through but after a while most will realise just how much they really miss these things and elect to return home if the right opportunity arises.
You are right to consider seniority and starting again from the bottom, but, hypothetically speaking, if you got your magic wand out now and knew you could get into BA but you would have to do say 7 years before you could leave and also that there would be a strong chance you would want to go to your national airline afterwards but you knew you could go there say, 4 years from today after training and flying a few tin cans for a while. Now tell me which is the better option for the
very long term? I know, all very hypothetical but hopefully you see my point. This game can often be '1 step forward, 2 steps back, 5 steps forward' etc etc at times.
And 'signing a contract with a clause of permanence', well what does that even mean? No employer can permanently handcuff you to a place or a job against your will. Well, maybe in North Korea..
Just wanted to offer a different perspective.