Thread by @fredguterl

Apparent weaknesses in the Russian military, and in President Vladimir Putin's standing abroad and at home, could increase the chance that Russia resorts to nuclear weapons in the conflict. "If the Russian campaign starts to feel like a military catastrophe..."

https://twitter.com/Newsweek/status/1500421988279586825

"...that's where escalation to nuclear weapons comes into play," says MIT's Barry Posen.

A nuclear conflagration is unlikely for the moment, but that's small solace, experts say:

"Probability is the wrong concept to apply to this situation," says @russianforces. "What seems impossible now could in fact happen. This was is a one-off irreproducible event."

Little is known about the dynamics of nuclear escalation on the battlefield, since it hasn't happened yet. At issue are Russia's 2000 or so tactical nuclear weapons, designed for use on the battlefield rather than on ICBMs.

"Nuclear weapons are back, but they never really went away," says @ProfTalmadge. "What's new in the present era is that the three great powers with nuclear weapons are entering a period of renewed competitive relationships...

"...We're talking about a world where in peacetime, in crisis and in conflict there is a nuclear shadow over states' interactions.

"We're getting a preview of that shadow in this war."

Escalation could happen inadvertently—the result of a moment's misunderstanding or miscalculation. Or if the war goes badly for Russia and its generals believe that the supplies coming in from the west are a problem, they could seek to interdict them by running airstrikes...

...along the Polish, Slovakian and Romanian borders. That would bring Russian jet fighters close to NATO's borders, increasing chances of direct conflict between nuclear nations.

What would NATO do then?

A no-fly-zone over Ukrainian territory would immediately escalate the conflict to one between NATO and Russia. "This all sounds like fantasy. It's not fantasy now. This is all very possible," says a military expert.

Although Putin's nuclear threats may be intended as deterrence, they can lead to "cycles of action and reaction on both sides," says @ProfTalmadge. Russians could read forward deployment by NATO nations as offensive in intent. Tensions rise, a shot is fired, and suddenly...

... Russia and NATO are in conflict.

The Ukraine war could presage rising nuclear tensions around the world. @OlyaOliker worries that Western nations will respond by building up NATO forces in Europe and preparing for a future conflict with Russia, which would raise the risks..

of a high-stakes confrontation. "The risk that a war goes nuclear is real."

Cold War fears of nuclear war are once again front and center. Future conflicts--along Russia's western border, off China's eastern coast--would also take place under a nuclear shadow.