How does the Canadian bilateral treaty differ with the one from the United States? Yes, it is kind of weird now to remember the Aer Lingus Boeing 707 scheduled service to Montreal and now no EI presence of any kind in Canada leaving it all to the summer flights of Air Canada's scheduled service and the Air Transat charters.
Air Canda has the high gross weight version of the A319 which they fly to cities in Colombia and Vezezuela so there should not be any problem with flying them from Toronto, Halifax or even St Johns, Newfoundland, with it's big Irish community, eastwards to Ireland on a limited year round basis even in winter on a two or three flights weekly frequency.
In the same way as the Air Canada narrow bodies doing some longhauls to South America would there be any case for a tiny fleet of new Boeing 737-900ERs for Aer Lingus to launch potential new routes to US East coast cities like Philadelphia and in time to some of the Atlantic coast cities of Canada?
As for Asia and South Africa, Cape Town and a big Chinese city like Shanghai would surely be a winner, twice weekly at a max to both cities. The best bet would be Boeing 777-200ERs if the Dublin runway can accomodate such a feat.
That 'R' word again! This all comes back to the massive crushing negative influence Shannon and it's lobby has had in Irish aviation and it still goes on and on. Weak governments and weak airports that have no guts to bring a change to this continuing farce.