Most h1bs at boeing will be restricted to internal IT support work. You need to be a US-person (citizen/greencard) for aircraft/military products.
Usually, H1-Bs aren’t supposed to work on core pieces like aircraft design software and such. This stuff is sensitive and subject to US laws. I know this because I interned at a similar defense company and most H1-Bs were limited to back-office IT apps and such.
This doesn’t even begin to make sense. First of all, everything a US company works on is “subject to US laws”. Second, where clearance is required, there is a bright line defining the rules, no “isn’t supposed to...”. Third, security clearances are available for foreigners as well.
Clearances are one piece. Trade restrictions like ITAR are another.