All defence contractors depend on smaller companies to supply them with things such as structural conponents, machined parts, hydraulic systems, electrical components, PCBs, electronic assemblies, waveguides...
I am thinking of the suppliers of the British parts in the Swedish Grippen and the Korean jet that prevented Argentina from acquiring those aircraft.
Will Government protect them? Aside from defence, I am thinking about things like:
Medical Equipment
Civil Aerospace
Civil Marine
Power Generation and Distribution
Industrial Machinery
Construction Equipment
Telecommunications and other Communications