Effects of de-alerting stategic nuclear weapons are analysed. Many different factors interplay, among others the size of arsenals and alertness level. Furthermore, the accuracy of the missiles as well as the hardness of silos play a certain role. These factors interplay in a way that may decrease stability of deterrence. Increasing the level of alert have impact on many factors which change the second strike probabilities and may highten the risk of use of nuclear weapons. The risks and outcomes should be compared with eventual gains from de-alerting if one wants to reduce not only the risk of use but the risk combined with the eventual outcome of the use.