All our efforts 'came to naught'. = ('US') All our efforts 'went for naught'. [=we did not succeed in doing what we were trying to do]
('chiefly US') It was 'all for naught'. [=it was all for nothing]
(..) The Ring is my burden. It will destroy you, Sam. Come on, Mr. Frodo. We best find you some clothes. You can't go walking through Mordor in naught but your skin. We did it, Mr. Frodo. We made it to Mordor. There are so many of them. We'll never get through unseen. It's him, the Eye. (..)2003 The Lord of the Rings: The Return of the King