a catch-22 situation a dilemma or difficulty from which there is no escape because of mutually conflicting or dependent conditions.

☞ The classic statement of this paradoxical situation is in Joseph Heller's novel Catch-22 (1961), from which the expression is taken: 'Orr would be crazy to fly more missions and sane if he didn't, but if he was sane he had to fly them. If he flew them he was crazy and didn't have to; but if he didn't want to he was sane and had to.' Heller's choice of the number 22 was purely arbitrary: there were no Catches-1 to 21.

2013Telegraph It's the ultimate catch 22, because if they do what Marine A was convicted of, then under British law you're a murderer. If you stay and try to treat him then potentially you and your team are going to get surrounded and killed.