FILE - In this image released by Russian Defense Ministry Press Service on Tuesday, May 21, 2024, a Russian Iskander missile is seen during drills to train the military for using tactical nuclear weapons at an undisclosed location in Russia. The world's nine nuclear-armed states continue to modernize their nuclear weapons as the countries continue to deepen their reliance on such deterrence in 2023, a Swedish think tank said Monday, June 17, 2024. (Russian Defense Ministry Press Service via AP, File)