Reciprocal second-strike capabilities usually cause a mutual assured destruction defence strategy, though one side may have a lower level minimal deterrence response.
The crucial goal in maintaining second-strike capabilities is preventing first-strike attacks from taking out a nation's nuclear arsenal.
Using SLBMs as a second-strike capability has a serious problem, because in retaliation for a submarine-launched ICBM, the wrong country could be targeted, and can cause a conflict to escalate.
Perimetr PTS dates back to 1974, in response to Soviet fears of devastating nuclear strikes from US ballistic missile submarines.
[citation needed] Russian ballistic missile submarines were reportedly never incorporated into Perimetr-PTS, given the inherent communication issues which could ensue.
In one episode, the US cabinet discusses the scenario of a Soviet surprise attack in which American cities would be destroyed, but the US armed forces would survive and launch a counter-attack.