Ukraine & former Soviet Nuclear Weapons
One blindingly obvious consequence of Putin’s war is the damage done to global arms control (try convincing Washington/NATO to reduce their defence efforts after what we've just witnessed). There’s also a more technical aspect, albeit with a very politicised element. It concerns steps in the 1990s to convince Ukraine to surrender the nuclear weapons option. This article nicely summarises key points.
Russian Nuclear Forces
Hot off the press: here's an up-date on Russian nuclear forces, from the Bulletin of the Atomic Scientists.
Israeli Nuclear Weapons
Here's a link to the latest reputable assessment of Israeli nuclear weapon capabilities. From Hans Kristensen and Matt Korda, published in the Bulletin of the Atomic Scientists.