I seriously doubt that the Marines were told to “remove clips”.
Well it is Obama/Kerry’s State Dept
I believe that we do not have all the facts, and may never have. I flew armed on many occasions in my military career, in uniform and in civilian clothes, with ammunition and without, on military and commercial aircraft. The USAF was probably the hardest to deal with, especially when flying on MAC charter (civilian) aircraft. Some of the things that they insisted we do were comical, but most people in the Air Force seldom come in contact with weapons. Foreign militaries were usually the easiest, so long as you didn't put a hole in their aircraft. Most commercial flights just wanted your weapon in a locked container, separated from the ammo and checked with baggage. That could be a problem if you are loading the aircraft under fire, but otherwise no sweat.
The biggest problem that I encountered was with customs and police at the airport. They could really get unhinged even if all your paperwork was in order. Yes, officer, I realize that's a fully automatic weapon, but it's not loaded and here's all of documents. I had a couple of guys thrown into the hoosegow in Oman on a Friday night because the embassy guy failed to show up at the airport as arranged. It took us until Sunday to get them sprung, their weapons back and on their way on an unscheduled flight.
Don't get me started on the stupid things that the State Department does.