That's their claim for how much less economic activity Iran (not just the government) had in total due to sanctions, not how much the government "spent on the nuclear weapons program" that could have instead been spent on desalination plants.
That's their claim for how much less economic activity Iran (not just the government) had in total due to sanctions, not how much the government "spent on the nuclear weapons program" that could have instead been spent on desalination plants.
But without a nuclear weapons program, the entire sanctions regime wouldn't have started (yea, I know today half of those are anti-terrorist sanctions, but that's not how it started, it was morphed later on). It should be considered as part of the losses.