This seems reasonable to me? If a western press were outside missile factories saying "this is the only place our super missiles are built!" I would expect the department of defence to block that information from being published...
(Please don’t flame thinking I’m hardcore in support of a particular side in this war due to this post—you’ve very likely gotten the wrong impression. I’m commenting only on the narrow point that the US in fact can censor, including with prior restraint in certain circumstances, during war.)
The United States's last declaration of war was 83 years ago. Since then it's been all "police actions" or some such. What meaning does "during war" carry in the world of today?