The only nation besides ourselves with sufficient warheads and delivery systems would be Russia, to my knowledge.
That's true, but not entirely correct.
The American stockpile of nuclear weapons peaked at more than 30,000 in 1966. If a superpower could do it 45 years ago, then major powers can do it today. Countries like Britain, France, Germany, Russia, China, India and Japan could each develop massive nuclear arsenals in the space of a few years -
if they wanted to.
Although there is some degree of parity in terms of sheer numbers of warheads, I believe that the Russian delivery systems have fallen far behind after the collapse of the Soviet Union.
There is no need for parity. All you need is a sufficient number of weapons to exterminate the enemy's large cities, taking into account losses from a first strike and missile defense.
The first can be reduced by using mobile or submarine launched missiles, the second is a joke against any serious strike.
Just an idle thought while I trek home: is it still a distinct and realistic risk that humanity could have a nuclear war? Not just a tactical use of them, in a battlefield situation, but a global exchange a la war games etc.
Any large scale war between major powers will be decided by nuclear weapons, or the threat of them. Which is why the US and Soviet Union had the good sense to never let the Cold War turn hot. They would both have lost.
It's a paradigm shift. WWII and all large scale wars before it were decided by which side could field the
most military power - in quantity and/or quality.
But nuclear weapons change the equation. It's no longer important to have more than your enemy, they're so powerful that you merely need to have
enough of them to destroy the enemy completely.
It worries me when Pentagon-spending is justified by citing the possibility of war with China. That feeds the illusion such a war could be decided by conventional weapons.
Rather than engage in technological countermeasures that they probably don't have the ability to keep up, I suspect they would respond by trying to increase their arsenal enough to overwhelm any strategic defense.
Missile defense against a serious nuclear strike is a joke.
Mid-course a ballistic missile splits into multiple warheads, and/or releases decoys - aluminum balloons with a small battery inside to produce an infrared signature. Such decoys are completely indistinguishable from the real warheads until they re-enter the atmosphere, and they can number up to a hundred. So for a mid-course intercept you need to attack each target, with an interceptor that is comparable in cost to a ballistic missile. That's doable only against a very small strike.
In the terminal phase ballistic missile's warheads move extremely fast, so they can only be intercepted by interceptors stationed near their target area. That means each target area requires its own extensive network of radar systems and missile launchers. That's doable to defend a small number of high-valued targets, but impossible to defend large civilian areas.
Additionally, as far as I'm aware missile defense systems have so far only been tested against individual, 'cooperative' ballistic missiles. Their reliability against a real attack, even a small one, is highly suspect.
And Russia has already developed a
missile to solve the problem:
The SS-27 is currently portrayed by Russian accounts as being immune to any ABM defense the United States can put into being. The missile is capable of making evasive maneuvers as it approaches its target, enabling it to evade any terminal phase interceptors. It almost certainly also carries countermeasures and decoys to decrease the chances of a successful targeting. The missile is shielded against radiation, electromagnetic interference and physical disturbance; [...] the SS-27 is designed to be able to withstand nuclear blasts closer than 500 m, a difficult interception when combined with the terminal phase speed and maneuverability. [...] And the SS-27 is also designed to survive a strike from any laser technology available, rendering any current space-based laser useless.
In my opinion Russia took the sane decision. It's much easier to develop a ballistic missile to overcome a ballisitic missile defense, than it is to develop said defense.