Between A Rock And A Hard Place Meaning

Example : 1970, David Sim, "Tangent":  Husbands, it seems to me, are caught between the Rock of Feminism and the Hard Place of their own marriages […]2008 Sept. 11, Eric Dash and Geraldine Fabrikant, "Washington Mutual stock falls on investor fears", New York Times (retrieved 24 Aug 2012):  If Washington Mutual needs to raise capital quickly, it will very likely find itself between a rock and a hard place, because credit markets have all but closed their doors to troubled banks.