The Pentagon now says 50 US troops in Iraq have been diagnosed with "traumatic brain injuries" after the Iranian missile strikes earlier this month on the military facility where they were based.
The United States originally announced that nobody had been hurt in the strikes that were in retaliation to the US assassination of Iranian General Qassem Soleimani.
But last week, the Pentagon said 34 people had been injured and that some were still receiving treatment.
US President Donald Trump was criticised following a news conference at the World Economic Forum in Davos, Switzerland, where he appeared to minimise their symptoms implying they had "headaches" that were not "serious".
Richard Weitz, a security and defence analyst at Wikistrat, a global risk consultancy, talks to Al Jazeera.