Russian Threat: Plans for Space-Based Nuclear Weapon

...There are two things that we'd be primarily worried about. A nuclear explosion in space is one of the most extreme counter space weapons that we can think of. So number one is the electromagnetic pulse that would immediately affect all satellites in the surrounding area. The second one is the environment of radiation that it would leave behind. So that would make sure that the satellites that are still in orbit are degraded much more rapidly than they otherwise would have been. We are hugely dependent on space - quite often to the extent that we don't even realise how dependent we are on space, so that includes emergency services, banking, but also as you said military capabilities. The vast majority of military capabilities couldn't function in the way that they do at the moment without space..."