I don't understand this conclusion. One book people aside, it is generally believed that humans evolved in an evolutionary context and they certainly frequently use cooperative strategies. Cooperation usually also involves the ability to sanction misbehavior. Unilateral disarmament is throwing away your sanction.
That depends on the circumstances. If you are arguing the case for unilateral disarmament or unilateral reduction. In many cases there was a deliberated attempt to confuse one with the other. Unilateral reduction can be the right move to make. In the case of a minor nuclear power such as the UK unilateral disarmament may be the right move if the force is insignificant and the cost of maintaining it is more than the ecconomy can afford or if it requires compromise of foreign policy in general to keep the supplier happy. Somehow I think it should be obvious that issues such as disarmament are rather more complex than a theoretical game theory model can capture. Theory should inform understanding, uncovering cause/effect relationships. That does not mean that all such relationships can be captured. The attempt to move from game theory to nuclear disarmament policy is a tenuous enough move which works primarily because both sides are rational actors who are employing the same ideological and analytical framework to achieve a common goal (avoiding mutual anihilation). It is an even more tenuous connection to apply it to the home burglar situation. Burglars are not rational actors, and are more likely to have their behaviour determined by drugs or alcohol than analytical game theory. The facts are very clear, if you have a handgun in the house it is far more likely to kill a member of the familly than stop an intruder. The NRA know this which is why they have lobbied for the CDC to stop research in this area - they do not like the facts. As someone who qualifies to be issued with a handgun under the UK regulations I have been informed that the protection offered is marginal at best. An intruder is certain to be more prepared than the intended victim, it is extreemly unlikely that the intruder will not get the first shot in. Phill