I can remember, as a kid way back in the 1970s, reading about plans to "make the desert bloom" by towing icebergs to arid regions. But, as far as I know, it has

I can remember, as a kid way back in the 1970s, reading about plans to "make the desert bloom" by towing icebergs to arid regions. But, as far as I know, it has never been done. Presumably logistics or politics got in the way. What makes this iteration of the idea any different?