This statement smelled fishy to me as there are only 40M or so people in Iraq to begin with, so I Googled around a bit.
Despite politicians and talking heads claiming for years that either Desert Storm, UN sanctions, or both caused half a million child deaths, evidently most studies found that the child mortality rate in Iraq was unchanged throughout the 1990s.
https://psmag.com/news/the-iraq-sanctions-myth-56433
https://cdn.factcheck.org/UploadedFiles/Iraqi-death-toll-doe...
While this apparently fake statistic has mostly been used to criticize the US and UN, it seems Tony Blair used it to justify the 2003 invasion of Iraq, claiming the dead kids were Saddam's fault.
I guess this is why I don't read the papers much anymore.