For submarines I assume the question is if those would be nuclear or diesel powered. If the former then that would probably be build by Naval group (which is majority owned by France and Thales has a stake in it) or if the latter Howaldtswerke-Deutsche Werft (German, owned by thyssenkrupp), who are e.g. also building the dolphin class subs for Israel. From an investment perspective neither would be a good pureplay though and I have no idea if theyd even have capacities to build more.

Airplanes would probably just be eurofighters, right? The only reason Germany is buying f35 is because they are certified to carry us nukes, not because the eurofighters would be incapable of being adapted to do so. The issue is that as I understand it certification would require the transfer of designs to the US, which obviously Germany and others don't want. So if anything that would mean shorting lockheed, if one assumes orders would/could get canceled.

Carrier rockets might be the most interesting aspect. I guess we'd be looking at ballistic missiles, if we are talking strategic nukes? In Europe the one company that would have some experience in that field is ArianeGroup (joint venture of Airbus and Safran). But again from a stock perspective seems like too small of a part of those companies to invest based on it.

There might be some small supplies that would be involved in projects like these, were a project like that would make a big impact, but I'd imagine that this type of company wouldnt be listed.