Which brings up another issue. They can't if the NG's aren't home to do it with. They are busy being foreign soil deployed. Their mission is being abused and that has been a major problem since Gulf War one. The problem of using NG's on a regular deployment basis has not been brought under control in the past 16 years. It's something Poppy Bush started up {yes I know other POTUS have used them also} using NG's rather than simply increasing permanent active duty strengths. Five years after 9/11 doing so though is ridiculous and just plain poor planning in the civilian leadership.
"yes I know other POTUS have used them also"
My father was in the TN National Guard and deployed to Mexico under "Black Jack" Pershing to chase Poncho Villa around before going to France in WWI. But I get your point.