Russia took over as the only nuclear state of the post-Soviet space.

Explanation:

- The dissolution of the Soviet Union in 1991 resulted in the emergence of several independent states in the post-Soviet space, including Russia, Ukraine, and Uzbekistan.
- In terms of nuclear capabilities, the Soviet Union was a nuclear superpower. It possessed a significant arsenal of nuclear weapons and had established a nuclear triad consisting of intercontinental ballistic missiles, strategic bombers, and ballistic missile submarines.
- After the collapse of the Soviet Union, the newly independent states had to decide what to do with the nuclear weapons and infrastructure that were located within their borders.
- Russia, as the successor state to the Soviet Union, inherited the majority of the nuclear weapons and infrastructure. This included the strategic nuclear forces, such as intercontinental ballistic missiles and ballistic missile submarines.
- Ukraine, which had the third-largest nuclear arsenal in the world at the time, voluntarily gave up its nuclear weapons and joined the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in 1994. This decision was made in exchange for security assurances from Russia, the United States, and the United Kingdom.
- Uzbekistan also had a small number of nuclear warheads on its territory, but it transferred them to Russia and joined the NPT in 1994.
- As a result, Russia became the sole possessor of nuclear weapons among the post-Soviet states. It retained a significant nuclear arsenal and continued to modernize its strategic forces.
- Russia's nuclear status has had implications for its regional influence and global security dynamics. It has remained an important player in international nuclear arms control and non-proliferation efforts.
- The other post-Soviet states, such as Ukraine and Uzbekistan, have since relied on the security guarantees provided by their membership in the NPT and diplomatic relations with nuclear-armed states like Russia and the United States.