Mark Gubrud Profile picture
Physicist, teacher, analyst & advocate in tech, arms control & human security. Idea man. Your broken Overton window is blighting the neighborhood. Dr./Dude/Dad
Sep 19, 2018 13 tweets 3 min read
Proponents of #SpaceForce think big. They thing space is big. But for security, #space is notably small. I explain.

Earth's land surface is divided into national territories. They're big enough to hide & hoard stuff & they can be controlled & defended by local regimes. + This applies to national airspace, too. It is actually becoming easier for nations to defend their airspace. As long as nations stay out of each others' airspace (without permission) there is no problem. But above 100 km or so this changes entirely. +