In XCOM: Enemy Within / Unknown if you choose to delay the Council mission to investigate the fishing village (full of chryssalids) as it's just too difficult for your current troops, does it ever come around again?
The last couple of games I've started I've gotten it extremely early so I don't want to keep risking soldiers getting killed when I have no Revive perks or decent weapons.
Best Answer
It will not, and you will incur in a massive FEAR penalty, which in turn will bite you at the end of the month as it's very likely for you to lose a country or two due to that.
The only missions that do recurr are the main story missions and EXALT (The main Exalt missions that is)