International flights require that you be at the airport at least three hours prior to the flights
It used to only be two hours, but with all the new precautions(I'm sure that's why its longer...)I plan on being at O'Hare by 1:30 p.m. for my 4:30 p.m. flight...stand in line,get checked in, etc.
Another thing to remember is that the ticketed passenger is the only person allowed past the security points into the gates
now. If you have friends or family sending you off, they won't get to wave to you from the gates
I hope this helps a bit.
Wyndyl