The screening apparently failed to turn up Alshamrani's exposure to jihadist ideology before coming to the U.S.
Defense Secretary Mark Esper wants to boost the number of foreign nationals training alongside U.S. troops by 50%.
The Pentagon has paused its training in the U.S. with Saudi nationals until officials conduct a thorough review.
Iraq's prime minister declared "final victory" over ISIS last year, but intense fighting continues.
About 90,000 Guard personnel lost valuable training in the shutdown.
BeaverFit's new Air Delivery Platform lets troops rappel from 60-foot towers built to mimic helicopter exits and skids.
Leaders realize the services will have to rely on video-game technology to meet their training needs.
The head of Air Force training said the service wants artificial intelligence to help airmen learn faster than ever before.
U.S. Army advisers in Afghanistan have learned they may want to focus more on training Afghan forces.
Even the Marines are facing problems with overweight troops.