'Dwarfed' would perhaps be too strong a term, but a 40-50% pay cut, coupled with the collapse of the USD against the GBP (2:1) and EUR (1.7:1) meant that a long haul BA skipper on a GBP140k (US$280k) - in currency terms probably upwards 30% more than their US counterparts who struggled to break 200k. This, of course, on top of having pensions worth millions stolen.
Now with the advent of huge profitability and new labor(u)r contracts, most wide body US legacy carrier captains (the vast majority being on top tier year 12 pay) are making about $300k (GBP 230k) under 'normal' rostering conditions, save for those who choose to work more or less). At current exchange rates, they're back out in front.
You're right that cohesive labour has been the backbone of the resurgence in pay rates. It's been hand in hand with the supply/demand see-saw swinging violently back into the pilots' favour. Unfortunately, on both counts, it doesn't bode well for Europe - where multiple jurisdictions make cohesion impossible, and a glut of pilots.
I'm not in the US, but have an active interest...