There was some stories back in 1989 … about the reliability of the Russian PALs. During perestroika, The US/west tried to assist in reducing the nuclear arsenal, and make it so that none of them would trigger without absolute control. That has been 30+ years ago, so my recollection may be hazy, but I know there were some efforts.

The problem with a warhead triggering accidentally, is that there could be massive amount of finger pointing about whose warhead just went off. Clancy wrote about the procedures in one of his books, that involve taking air samples of the debris, to try to determine the source(s) of the fissile material. If Clancy got the story right, we had better all hope that sanity prevails until such time as the details can be sorted out.

When Russia was using nuclear capable cruise missiles a few weeks back, there were substantial comments that the debris field around the impact contained no radioactive material. Apparently Ukraine (or someone with long range weapon identification capability) realized rather quickly what type they were, and wanted to tell equally quickly if they were a deliberate non-warhead payload, or a real payload that failed to detonate. Crappy world we live in when those questions need to be answered in minutes.