Arguably, any such clauses - similar to attempt for "non commercial" licenses would do more harm than good.

If you actually wanted to respect such a license,you would have to endlessly argue what is dual use technology for example, the same as people argue if advertisements on project website or tangentially related donations make the thing "commercial"?

While at the same time, any "bad guys" will just ignore both.

The idea that a defense manufacturer would be stopped by this is too funny. The code won't be auditable by you so how will you know? Secondly even if you did find out the most you'd get is a payout. Thirdly if you believe that missile aren't running GNU/Linux I have a bridge to sell you.

I've contemplated writing an email to RMS asking him how he feels about the use of GNU software in military and surveillance systems and if he could do it over if he would do things differently to alllow users to put a clause in their OSS licenses that forbid such things.