THE DEFENSE DEPARTMENT disclosed on Friday that 34 U.S. servicemembers have been diagnosed with concussions or traumatic brain injuries since the Iranian ballistic-missile strike earlier this month against the al-Asad air base in Iraq. It’s good that the Pentagon finally decided to provide more information about the number of troops hurt and the extent of their injuries. But we hope that their commander in chief recognizes the need to revise his recent ill-advised remarks minimizing the seriousness of brain injuries. Whether intentionally or not, the comments by President Trump fed into age-old stereotypes and undercut the Pentagon’s own efforts to deal with this critical issue.

Friday’s briefing by Defense Department spokesman Jonathan Hoffman, which revealed that eight service members were flown to the United States for treatment, nine were still being treated in Germany and the rest had been returned to duty, was the most complete to date. Soon after the Jan. 8 missile strike, Mr. Trump reported that no Americans had been harmed in the attack, a reprisal for the U.S. airstrike in Baghdad that killed Iranian Maj. Gen. Qasem Soleimani. In the weeks that followed, military officials acknowledged that troops — said to be “in the teens” — were being treated for concussion symptoms. Officials said the delay in reporting was because of the time it took for the information to work is way up the chain of command and that brain-injury symptoms are not always immediately apparent.

But when the president was asked about this Wednesday at a news conference in Davos, Switzerland, he said, “I heard they had headaches. No, I don’t consider them very serious injuries relative to other injuries that I’ve seen. I’ve seen people with no legs and no arms.” The comments understandably caused concern because they conflict with mounting medical evidence that even seemingly mild brain injuries, particularly repeat ones, can have long-term, debilitating effects. The remarks run counter to the military’s efforts to call attention to and take seriously these invisible wounds of war.

The Pentagon has labeled traumatic brain injuries, or TBIs, a “signature” injury of the wars in Iraq and Afghanistan and is devoting millions of dollars for research and treatment. A major hurdle has been to destigmatize brain injury and make people realize that injuries to the brain that can’t be seen are just as serious — and sometimes more difficult to treat — than bloody wounds to other parts of the body.

More than 413,000 servicemembers since 2000 have experienced brain injuries from a variety of causes, according to the Pentagon’s Defense and Veterans Brain Injury Center. Mr. Trump owes it to them — and all the brave men and women who put their lives and health at risk for the country — to correct his comments and make clear that brain injuries must be taken seriously.

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