and it is ill-equipped to do so And why, after going on 5 years, are we ill equipped? Why?
From the Washington Post:

About 1,800 U.S. troops, according to the Department of Veterans Affairs, are now suffering from traumatic brain injuries (TBIs) caused by penetrating wounds. But neurologists worry that hundreds of thousands more — at least 30 percent of the troops who’ve engaged in active combat for four months or longer in Iraq and Afghanistan — are at risk of potentially disabling neurological disorders from the blast waves of IEDs and mortars, all without suffering a scratch.

For the first time, the U.S. military is treating more head injuries than chest or abdominal wounds, and it is ill-equipped to do so. According to a July 2005 estimate from Walter Reed Army Medical Center, two-thirds of all soldiers wounded in Iraq who don’t immediately return to duty have traumatic brain injuries.

Here’s why IEDS carry such hidden danger. The detonation of any powerful explosive generates a blast wave of high pressure that spreads out at 1,600 feet per second from the point of explosion and travels hundreds of yards. The lethal blast wave is a two-part assault that rattles the brain against the skull. The initial shock wave of very high pressure is followed closely by the “secondary wind”: a huge volume of displaced air flooding back into the area, again under high pressure. No helmet or armor can defend against such a massive wave front.