Haven’t tweet much on Ukraine crisis for multiple reasons. But developments in the last 24 hours are heartbreaking and a preview of great brutality I fear is coming. A few observations here on the nuclear & conventional dimensions. 1/

Putin’s pointed, not-veiled nuclear threats are really remarkable, signaling a willingness to turn to the country’s arsenal if the West interferes with the Russian invasion of Ukraine. 2/
https://t.co/M3Ema8WQER

This is about the clearest evidence I have ever seen for the Stability-Instability Paradox: the notion that mutual vulnerability ("MAD") at the strategic nuclear level can actually make conflict more likely at lower rungs of the escalation ladder. 3/

Deterrence theorists associated with the Nuclear Revolution often dismiss this idea, arguing that nuclear stalemate means both sides will avoid crises and conflicts out of the fear they could escalate. The result should be peace, stability, and less military competition. 4/

Yet Putin’s behavior suggests that revisionist actors are not so inhibited and may instead use their strategic nuclear forces as a shield behind which they can pursue conventional aggression, knowing their nuclear threats may deter outside intervention. 5/

Now of course, Ukraine is not a member of NATO, nor a U.S. treaty ally. But then neither is Taiwan. So if you think nuclear stalemate is going to keep the peace in the Strait, you would need to do some hard thinking about why it hasn’t kept the peace in Eastern Europe. 6/

China, in fact, is developing the same types of forces that Putin references in his remarks: not only a survivable second-strike capability, but also theater nuclear forces suited for limited strikes for coercive escalation. Not a coincidence. 7/
https://t.co/TUoMrw5YPF

More broadly, as a student of military operations and foreign policy, it’s hard for me to see the Russian end game here either operationally or strategically, for reasons @jeffaedmonds and @KofmanMichael and others have identified. 8/
https://t.co/1Ps68eg2TN

Yes, at a tactical level Russia can steamroll Ukrainian regular forces, though I expect Ukraine can make this more costly than Russia has anticipated. Urban warfare is unkind to invaders, even strong ones. 8/
https://t.co/WYS7tRfjI8

But beyond that, what is military endgame? Regime change and then puppet government? Difficulties of indefinitely occupying a nation of 41 million should be apparent after Soviet experiences with Warsaw Pact & Afghanistan, among others @dmedelstein. 9/
https://t.co/OIRNY2jbuL

Russian invasion likely to provoke higher European defense spending, tighter NATO, deployment of NATO forces east, hostility with West. Ukraine was not headed for NATO membership any time soon, so a destabilizing invasion wasn’t necessary to forestall that perceived danger. 10/

At the strategic level, Russian invasion gives off big Schlieffen Plan energy. It is like committing suicide for fear of death, bringing about the very problems it is supposed to solve, and generating new ones like risks of inadvertent escalation. 11/11