My wife and I are going to Tel Aviv in December only because I just kept checking the awards on Delta.com and finally found Business seats available non-stop from JFK to TLV that would work. I nabbed those and then went back and got seats from STL to JFK (well, actually LGA on the way). We have an overnight in NYC on the way out (visiting friends) and then about 7 hours at JFK on the way home between flights. That seemed like plenty of time to get through customs and re-check the bags and all to STL.

Stories about long waits at immigration got me a little nervous and I assumed I would be better off if there was a disruption if the two itineraries were merged. Almost all my travel is domestic so my experience on international flights is limited. I called Delta and was told that the two could not be combined once the reservations were made.

Is that correct and if not, do I really need to worry about it?