For the first time since the fall of the Soviet Union, Russian tactical nuclear weapons are being deployed outside the country’s borders. Russian President Vladimir Putin said he’s deploying the weapons because the U.K. gave armor-piercing shells containing depleted uranium to Ukraine.

Russian President Putin has announced today that they will soon begin Deploying a number of Tactical-Nuclear Weapons into the Territory of Belarus; these Weapons will most likely be launched from 9K720 Iskander Missile Systems. pic.twitter.com/VuszqeQAhk

— OSINTdefender (@sentdefender) March 25, 2023

Most people are familiar with strategic nuclear weapons: large devices with massive payloads designed to wipe out entire cities. There is still a debate about how exactly to define tactical nuclear weapons (TNWs). It’s generally accepted TNWs are used for specific tactical gains on the battlefield.

TNWs are designed to destroy enemy troops, weapons and equipment. They generally have a shorter range and much lower yield than strategic nuclear weapons.

Many of Russia’s weapons delivery systems can be used to launch both conventional payloads and tactical nukes. So, Russia can use its Iskander mobile short-range ballistic missile system to deliver a tactical nuclear strike, as well as a torpedo from a submarine, or a missile launched from a fighter jet.

Russia and Belarus have strong military ties. The president of Belarus, Alexander Lukashenko, allowed Putin to stage Russian troops in Belarus before the invasion of Ukraine in 2022. Putin said Saturday, March 25, Lukashenko has been asking for some time for Russia to deploy nuclear weapons on Belarusian soil.

#Belarus: Armed Forces of Belarus completed the formation of a new S-300PS anti-aircraft missile regiment.

The regiment has been deployed on the territory of a military airfield in Luninets, Brest Region, approx. 50km from the border with Ukraine. pic.twitter.com/xletvdlOFx

— Status-6 (@Archer83Able) March 28, 2023

Belarus already has Iskander launchers from Russia, and the Russian Ministry of Defense said 10 Belarusian fighter jets had already been upgraded to carry tactical nuclear payloads.

When the USSR fell apart in 1991, Russia had around 22,000 tactical nukes. Today, that number is believed to be closer to 2,000, which is still 10 times as many as the U.S.

Russia threatening the use of nuclear weapons isn’t anything the world hasn’t heard before. The nuclear saber rattling has been consistent throughout the war in Ukraine, which is one reason why the U.S. said it isn’t changing its nuclear posture regarding Putin’s announcement.

It may be a different story in China, though. Just four days before Putin announced he would put nukes in Belarus, he signed a declaration with Chinese leader Xi Jinping that said a nuclear war must never take place, and that there are no winners in a nuclear conflict.

Both Putin and Lukashenko humiliated Xi . Remember, Luka was just treated to a fancy state visit to China. Xi just came to Moscow. Can’t imagine this decision is going down well in Beijing. https://t.co/lyGx93PeDJ

— Michael McFaul (@McFaul) March 26, 2023

Former U.S. ambassador to Russia, Michael McFaul, said Russia and Belarus humiliated Xi Jinping. Now, the world waits to see how that humiliation will manifest.

The Associated Press contributed to this report.