Hypersonic flight is not new. The V-2 rocket and the vast majority of the ballistic missiles that it inspired achieved hypersonic speeds (i.e., speeds faster than the speed of sound or Mach 5+) as they fell from the sky, as did crewed aircraft like the rocket-powered X-15. Rather than speed, today’s renewed attention to hypersonic weapons owes to developments that enable controlled flight. These new systems have two sub-varieties: hypersonic glide vehicles and hypersonic cruise missiles. Glide vehicles are the cousins of ballistic warheads: they are lofted on high velocity boosters, separate, then use momentum and control surfaces to skip and glide through the upper atmosphere before crashing onto their targets. The cruise missiles use an advanced propulsion system (a SCRAMJET) for powered flight. While the descriptions are straightforward, the engineering needed to accomplish the guidance and maneuvering (not to mention survivability) of these weapons is far from clear.
There are three sets of reasons for a palpable rise in nuclear anxieties around the world: growing nuclear arsenals and expanding roles for nuclear weapons, a crumbling arms-control architecture, and irresponsible statements from the leaders of some nuclear-armed states.
The second nuclear summit between President Donald Trump and North Korean leader Kim Jong Un ended abruptly last week with no deal and no plan for North Korean denuclearization. When asked how he had discussed the matter with Kim, Trump responded by noting, “denuclearization is a very important word, has become a very well-used word. A lot of people don’t know what it means but to me it’s pretty obvious we have to get rid of the nukes.”
This graphic outlines the key rapprochement-related events between North Korea and South Korea since the 1972 reunification talks. For more, read Linda Maduz’s recent CSS Analyses in Security Policy on the prospects for rapprochement on the Korean Peninsula here. For more CSS charts and graphics, click here.
A more competitive international environment, and in particular Russia’s assertive policies, have sparked renewed interest in the concept of nuclear deterrence as part of NATO’s approach to security. This has manifested itself in devoting greater attention to Russia’s nuclear policy and posture as well as to NATO’s own nuclear arrangements, and in a stronger emphasis on nuclear deterrence in public statements. However, this renaissance of nuclear deterrence takes place against the backdrop of new developments that seek to challenge the military rationale and moral legitimacy of that very concept. Put differently, just as nuclear deterrence is again becoming more important, it is also becoming more contested.