Originally Posted by
zambonidriver
How can they be so certain about what was actually affixed to those pylons?
Short of some extremely sensitive instruments which seem beyond airborne use in a fighter it is at best an estimate.
Not to endorse any of the recent Russian activities but let's keep it factual.
I am also skeptical that Sweden would be able to confirm that an Su-24 was carrying a nuclear weapon with optical imagery. Perhaps something was lost in translation. There is a difference between a nuclear-capable delivery vehicle (e.g., gravity bomb, cruise missile) and the associated nuclear warhead. I am not aware of any nuclear weapon where the presence of a nuclear warhead can be confirmed by external inspection. Even retired systems such as the Polaris SLBM or Russian SS-N-6 that had an external reentry vehicle (RV), you still couldn't tell by external inspection if the RV contained a nuclear warhead. The standard method to confirm the presence of a nuclear warhead in arms control regimes is by using radiation detection equipment. Doubt the Gripens got close enough to use that scheme.