As Russia's Ukraine war intensifies, some warn nuclear escalation is possible

A ground-based intercontinental missile will be tested in 2020. Russia has the largest nuclear arsenal.

Russian Defense Ministry Press Service /AP

Russian President Putin gave orders to his nuclear forces over the weekend. The U.S. said it wouldn't change its nuclear posture.

White House Press Secretary Jen Psaki told reporters on Monday that there was no reason to change alert levels.

Some experts are concerned about the possibility of a nuclear war. Here is why.

The exact meaning of Putin's order remains unclear

Putin is shown speaking to two generals about the country's nuclear forces.

The senior researcher at the United Nations Institute for Disarmament says that he was told that we should start this special mode of combat because of all the hostile statements.

It is not clear what a special mode of combat duty is. One possibility is that the order activated the nation's nuclear command and control system.

In peacetime, the command and control system is configured in a way that makes it hard to send a command.

The button may have been activated because of Putin's order.

It may not.

The Russian Ministry of Defence implied in a follow-up statement that it meant to increase staffing at facilities that support nuclear weapons. They just added a few more people to the crews.

Russia has a lot of nuclear weapons at the ready

The director of the nuclear information project at the Federation of American Scientists said that Russia has more nuclear weapons than any other nation.

He says they have about 4,500 nuclear warheads in their military arsenal.

Russia's largest nukes appear to be at their usual level of alert for now. The nation has nearly 2,000 tactical nuclear weapons, which are kept in storage facilities throughout Russia.

Russia is using its Iskander missile system in the conflict in Ukraine. It can launch both missiles and nuclear weapons.

Russian Defense Ministry Press Service/AP

They were developed to fight a limited battle. It was sort of a nuclear war in a small area.

The U.S. has around 100 nuclear bombs in Europe that could be used for tactical nuclear warfare.

Russia is currently bombarding Ukraine with its Iskander missile, which can be launched on the same short-range missiles the Kremlin can use.

There is no indication that the nukes are out of storage.

Russia says it would only use nukes as a last resort, but some are skeptical

Russia says it would only use nuclear weapons if it was in danger. Some people don't think the nuclear rules are clear-cut.

A lot of people have questioned whether the bar for Russian nuclear use is as high as the official statements say.

Russia might use a battlefield nuke to de-escalate a conflict on terms favorable to Russia, according to the Pentagon's nuclear posture review.

It was a controversial statement among arms control experts at the time. It would only happen in a war with NATO.

She says that it is unlikely that Moscow will use a nuclear weapon in the current conflict with Ukraine.

The risk of miscalculation is higher than it's been in years

Jeffrey Lewis is a senior scholar at the Middlebury Institute of International Studies at Monterey.

He says that Putin has had a pretty bad week. They areindiscriminately shelling civilians. Those things make him look weak, and the best way to push those headlines down is a nuclear threat.

Lewis says there is still a lot of nuclear risk. Putin underestimated his invasion of Ukraine.

If the Russian warning system had a false alarm, what would happen? Would he jump to the wrong conclusion?

Thousands of Russian and American long-range missiles are ready to launch in just minutes even if the short-range battlefield nukes are still on the shelf. As the conflict in Ukraine drags on, that threat hangs over everything.