The war analogy is not really adequate. War is an extension of diplomacy, a continuation of policy with other means, an instrument that may allow politicians to

The war analogy is not really adequate. War is an extension of diplomacy, a continuation of policy with other means, an instrument that may allow politicians to achieve certain foreign policy goals which they could not otherwise. War is not something that magically happens on it's own, it's started intentionally to achieve certain goals, by a politician who did not want to stop that war but who wanted and chose to start it. Even in the absence of actual conflict, having that option (and others knowing that you have that option) gives you lots of leverage and influence, and unilaterally abandoning that capability gives up that influence and ensures that you'll have to concede things to others who do have that option. And it's not just that unilateral withdrawal doesn't work (si vis pacem, para bellum), but also that a multilateral agreement to end all war and capability for it is not something that all politicians and countries desire - some do, but some countries are militarily more capable than others, and they benefit from that, so it's simply not in their best interest to have a world where war isn't an option and they lose that influence. Case in point - nuclear disarmament; the powers that do have nuclear weapons have a strategic advantage over those that don't, and they would not be willing to give that up to have a world with no nuclear weapons even if it would be possible to have a working multilateral agreement between all of the nuclear powers.