Is this the point we need to worry?
The extremely high speeds hypersonic weapons travel at reduce an adversary's ability to react to them. Suppose two nuclear-armed countries—let's call them India and Pakistan—have hypersonic weapons and nuclear weapons. Both weapons are located in each country's capital. A hypersonic missile launched from Pakistan's capital, Islamabad, will reach the Indian capital of New Delhi in just over six minutes.
Launching your own missiles upon detecting incoming missiles--regardless of whether the missiles are nuclear or even real (it could be a mistake in the detection gear or a decision by someone in the chain of command to claim missiles are inbound)--might be the only solution.
But the situation of short decision times is already here between Pakistan and India. There is no need to wait for hypersonic weapons.
And the key is to have survivable nuclear weapons that allow each side to ride out an enemy disarming strike and still have surviving weapons capable of launching a counter-strike after it is clear the enemy has used nuclear weapons:
We really need to get Indian and Pakistani nuclear policy people to study our long history of thought on this subject from the Cold War.
The sooner India and Pakistan focus on smaller but survivable nuclear deterrents rather than starting an offensive arms race (to make sure something survives a disarming strike) that drags in China--which then might pull in Japan, Taiwan, South Korea and then Australia and Indonesia--the better.
Nuclear-armed subs are survivable--if command and control can be assured and if nobody thinks a sub sinking from an accident is a preemptive strike. But I wonder if either could have enough to really make a survivable deterrent. Britain and France have enough of a problem deploying a sub with their tiny sea-based nuclear deterrents.
India could probably increase their survivability by putting some ballistic missiles on their Andaman or Nicobar Islands.
But where could Pakistan put land-based missiles with some strategic depth from Indian land-based missiles? Could Pakistan lease Socotra from Yemen for 50 years? Perhaps Pakistan pays for this with ground troops deployed in Yemen as a sort of peacekeeping force once the civil war their is settled.
And of course, well-protected silos would help. But mobile missiles are an invitation to theft, I think.
