Out of the some 18x (that I could find), the phrase "all the nations [PLURAL]" (like in the passage under discussion), it is never written in the contexts so as to be pointing out the singular nation "Israel":
--Matt24:9,14; 25:32; 28:19; Mk11:17; 13:10; Lk21:24; 24:47; Ac14:16; 17:26; Rom1:5; 16:26; Gal3:8; Rev12:5; 14:8; 15:4; 18:3,23